Cathode materials in microbial electrosynthesis systems for carbon dioxide reduction: recent progress and perspectives

Abstract

Microbial electrosynthesis (MES) is an emerging technology that enables the synthesis of value-added chemicals from carbon dioxide (CO₂) or inorganic carbon compounds by coupling renewable electricity to microbial metabolism. However, MES still faces challenges in achieving high production of value-added chemicals due to the limited extracellular electron transfer efficiency at the biotic-abiotic interfaces. To overcome this bottleneck, it is crucial to develop novel cathodes and modified materials. This review systematically summarizes recent advancements in cathode materials in the field of electrocatalyst-assisted and photocatalyst-assisted MES. The effects of various material types are further investigated by comparing metal-free and metal materials and photocatalyst materials of different semiconductor types. Additionally, the review introduces the maximum production rate of value-added chemicals and conversion efficiency achieved by these cathode materials while highlighting the advantages and disadvantages of different material types. To the best of our knowledge, in electrocatalyst-assisted systems, the maximum CH₄ yield on graphene aerogel/polypyrrole cathode achieved 1,672 mmol m^-2 d^-1, and the maximum Faraday efficiency (FE) of CH₄ reached up to 97.5% on graphite plate. Meanwhile, the maximum acetate yield achieved 1,330 g m^-2 d^-1 with CO₂ conversion efficiency into acetate close to 100% on carbon nanotube cathodes. In photocatalyst-assisted systems, the maximum acetate yield could reach 0.51 g L^-1 d^-1 with the coulombic efficiency of 96% on the MnFe₂O₄/g-C₃N₄ photocathode. Finally, prospects for future development and practical applications of MES are discussed, offering theoretical guidance for the fabrication of cathode materials that can improve production efficiency and reduce energy input.

Keywords

Microbial electrosynthesis / cathode materials / electrochemically active microorganisms / extracellular electron transfer / photocatalyst

References

[1] Liao JC,Pontrelli S.Fuelling the future: microbial engineering for the production of sustainable biofuels.Nat Rev Microbiol2016;14:288-304

[2] Davis SJ,Matthews HD.Future CO₂ emissions and climate change from existing energy infrastructure.Science2010;329:1330-3

[3] Turner JM.The matter of a clean energy future.Science2022;376:1361

[4] Fu J,Lin Y.Fight for carbon neutrality with state-of-the-art negative carbon emission technologies.Eco-Environ Health2022;1:259-79

[5] Nevin KP,Franks AE,Lovley DR.Microbial electrosynthesis: feeding microbes electricity to convert carbon dioxide and water to multicarbon extracellular organic compounds.mBio2010;1:e00103-10 PMCID:PMC2921159

[6] Prévoteau A,Ganigué R.Microbial electrosynthesis from CO₂: forever a promise?.Curr Opin Biotechnol2020;62:48-57

[7] Rabaey K.Microbial electrosynthesis - revisiting the electrical route for microbial production.Nat Rev Microbiol2010;8:706-16

[8] Wang R,Sun J.Nanomaterials facilitating microbial extracellular electron transfer at interfaces.Adv Mater2021;33:e2004051

[9] Tan X.The integration of bio-catalysis and electrocatalysis to produce fuels and chemicals from carbon dioxide.Chem Soc Rev2022;51:4763-85

[10] Zeng AP.New bioproduction systems for chemicals and fuels: needs and new development.Biotechnol Adv2019;37:508-18

[11] Jourdin L.Microbial electrosynthesis: where do we go from here?.Trends Biotechnol2021;39:359-69

[12] LaBelle EV,May HD.Microbiome for the electrosynthesis of chemicals from carbon dioxide.ACC Chem Res2020;53:62-71

[13] Jiang Y,Li H,Song B.Harnessing microbial electrosynthesis for a sustainable future.Innov Mater2023;1:100008

[14] Borole AP,Ringeisen B,Feng Y.Electroactive biofilms: current status and future research needs.Energy Environ Sci2011;4:4813-34

[15] Chatterjee P,Kokko M,Lens P.Selective enrichment of biocatalysts for bioelectrochemical systems: a critical review.Renew Sustain Energy Rev2019;109:10-23

[16] Bajracharya S,Matsakas L,Christakopoulos P.Advances in cathode designs and reactor configurations of microbial electrosynthesis systems to facilitate gas electro-fermentation.Bioresour Technol2022;354:127178

[17] Aryal N,Patil SA.An overview of cathode materials for microbial electrosynthesis of chemicals from carbon dioxide.Green Chem2017;19:5748-60

[18] Bian B,Xu J,Saikaly PE.Microbial electrosynthesis from CO₂: challenges, opportunities and perspectives in the context of circular bioeconomy.Bioresour Technol2020;302:122863

[19] Jourdin L,Donose BC.A novel carbon nanotube modified scaffold as an efficient biocathode material for improved microbial electrosynthesis.J Mater Chem A2014;2:13093-102

[20] Wu B,Kang X,Dobson AD.Improved robustness of ex-situ biological methanation for electro-fuel production through the addition of graphene.Renew Sustain Energy Rev2021;152:111690

[21] He Y,Zhang L.3D-printed GA/PPy aerogel biocathode enables efficient methane production in microbial electrosynthesis.Chem Eng J2023;459:141523

[22] Alqahtani MF,Bajracharya S,Lai Z.Porous hollow fiber nickel electrodes for effective supply and reduction of carbon dioxide to methane through microbial electrosynthesis.Adv Funct Mater2018;28:1804860

[23] Zhu X,Bian Y,Tsesmetzis N.Electrocatalytic membranes for tunable syngas production and high-efficiency delivery to biocompatible electrolytes.ACS Sustain Chem Eng2021;9:6012-22

[24] Qiu Z,Li XL,Xie J.Sn promotes formate production to enhance microbial electrosynthesis of acetate via indirect electron transport.Bio-Chem Eng J2023;192:108842

[25] Liu X.Carbon-based metal-free catalysts.Nat Rev Mater2016;1:16064

[26] Zhao Y,Kamiya K,Hashimoto K.Nitrogen-doped carbon nanomaterials as non-metal electrocatalysts for water oxidation.Nat Commun2013;4:2390

[27] Liu J,Liu N.Metal-free efficient photocatalyst for stable visible water splitting via a two-electron pathway.Science2015;347:970-4

[28] Lekshmi GS,Ramakrishna S.Microbial electrosynthesis: carbonaceous electrode materials for CO₂ conversion.Mater Horiz2023;10:292-312

[29] Wickramaarachchi K,Aravindh SA.Repurposing N-doped grape marc for the fabrication of supercapacitors with theoretical and machine learning models.Nanomaterials2022;12:1847 PMCID:PMC9182344

[30] Yuan Y,Fu P,Zhou S.Conversion of sewage sludge into high-performance bifunctional electrode materials for microbial energy harvesting.J Mater Chem A2015;3:8475-82

[31] You PY.Recent progress of carbonaceous materials in fuel cell applications: an overview.Chem Eng J2017;309:489-502

[32] Li S,Thomas A.Carbon-based microbial-fuel-cell electrodes: from conductive supports to active catalysts.Adv Mater2017;29:1602547

[33] Kadier A,Abdeshahian P.Recent advances and emerging challenges in microbial electrolysis cells (MECs) for microbial production of hydrogen and value-added chemicals.Renew Sustain Energy Rev2016;61:501-25

[34] Zhen G,Kumar G,Xu K.Microbial electrolysis cell platform for simultaneous waste biorefinery and clean electrofuels generation: Current situation, challenges and future perspectives.Prog Energy Combust Sci2017;63:119-45

[35] Cheng S,Call DF.Direct biological conversion of electrical current into methane by electromethanogenesis.Environ Sci Technol2009;43:3953-8

[36] Ni J.Carbon nanomaterials in different dimensions for electrochemical energy storage.Adv Energy Mater2016;6:1600278

[37] Jin H,Liu X.Emerging two-dimensional nanomaterials for electrocatalysis.Chem Rev2018;118:6337-408

[38] Marshall CW,Fichot EB,May HD.Long-term operation of microbial electrosynthesis systems improves acetate production by autotrophic microbiomes.Environ Sci Technol2013;47:6023-9

[39] Villano M,Aulenta F.Carbon and nitrogen removal and enhanced methane production in a microbial electrolysis cell.Bioresour Technol2013;130:366-71

[40] Dong Z,Tian S.Fluidized granular activated carbon electrode for efficient microbial electrosynthesis of acetate from carbon dioxide.Bioresour Technol2018;269:203-9

[41] Fan Q,Sun T.Advances of the functionalized carbon nitrides for electrocatalysis.Carbon Energy2022;4:211-36

[42] Shakeel S,Khan MZ.Nitric acid treated graphite granular cathode for microbial electro reduction of carbon dioxide to acetate.J Cleaner Prod2020;269:122391

[43] Chen LF,Zhang J.A short review of graphene in the microbial electrosynthesis of biochemicals from carbon dioxide.RSC Adv2022;12:22770-82 PMCID:PMC9376761

[44] Qiu HJ,Luo P.Recent advance in fabricating monolithic 3D porous graphene and their applications in biosensing and biofuel cells.Biosens Bioelectron2017;89:85-95

[45] Strübing D,Mößnang B,Drewes JE.Anaerobic thermophilic trickle bed reactor as a promising technology for flexible and demand-oriented H₂/CO₂ biomethanation.Appl Energy2018;232:543-54

[46] Deutzmann JS,Gu W.Microbial electrosynthesis of acetate powered by intermittent electricity.Environ Sci Technol2022;56:16073-81

[47] Guo S,Bianco A.Controlling covalent chemistry on graphene oxide.Nat Rev Phys2022;4:247-62

[48] Wu J,Moss DJ,Jia B.Graphene oxide for photonics, electronics and optoelectronics.Nat Rev Chem2023;7:162-83

[49] Lin T,Sun L,Liu CG.Engineered shewanella oneidensis-reduced graphene oxide biohybrid with enhanced biosynthesis and transport of flavins enabled a highest bioelectricity output in microbial fuel cells.Nano Energy2018;50:639-48

[50] Yong YC,Zhang X.Highly active bidirectional electron transfer by a self-assembled electroactive reduced-graphene-oxide-hybridized biofilm.Angew Chem Int Ed2014;53:4480-3

[51] Choi S,Suh JM.Reduced graphene oxide-based materials for electrochemical energy conversion reactions.Carbon Energy2019;1:85-108

[52] Song TS,Liu H.High efficiency microbial electrosynthesis of acetate from carbon dioxide by a self-assembled electroactive biofilm.Bioresour Technol2017;243:573-82

[53] Chen L,Mohanty S,Zhang T.Electrosynthesis of acetate from CO₂ by a highly structured biofilm assembled with reduced graphene oxide-tetraethylene pentamine.J Mater Chem A2016;4:8395-401

[54] Katuri KP,Kavanagh P.Electroactive biofilms on surface functionalized anodes: the anode respiring behavior of a novel electroactive bacterium, Desulfuromonas acetexigens.Water Res2020;185:116284

[55] Zhang T,Bain TS.Improved cathode materials for microbial electrosynthesis.Energy Environ Sci2013;6:217-24

[56] Flexer V,Donose BC,Wallace GG.The nanostructure of three-dimensional scaffolds enhances the current density of microbial bioelectrochemical systems.Energy Environ Sci2013;6:1291-8

[57] Flexer V.Purposely designed hierarchical porous electrodes for high rate microbial electrosynthesis of acetate from carbon dioxide.ACC Chem Res2020;53:311-21

[58] Logan B,Watson V.Graphite fiber brush anodes for increased power production in air-cathode microbial fuel cells.Environ Sci Technol2007;41:3341-6

[59] Liu C,Gu Y.Enhancement of bioelectrochemical CO₂ reduction with a carbon brush electrode via direct electron transfer.ACS Sustain Chem Eng2020;8:11368-75

[60] Baek G,Logan BE.Addition of a carbon fiber brush improves anaerobic digestion compared to external voltage application.Water Res2021;188:116575

[61] Fan X,Jin X,Li Z.Carbon material-based anodes in the microbial fuel cells.Carbon Energy2021;3:449-72

[62] Vidales AG, Omanovic S, Li H, Hrapovic S, Tartakovsky B. Evaluation of biocathode materials for microbial electrosynthesis of methane and acetate.Bioelectrochemistry2022;148:108246

[63] Ameen F,Nadhari SA.Effect of electroactive biofilm formation on acetic acid production in anaerobic sludge driven microbial electrosynthesis.ACS Sustain Chem Eng2020;8:311-8

[64] Zhen G,Kobayashi T,Xu K.Promoted electromethanosynthesis in a two-chamber microbial electrolysis cells (MECs) containing a hybrid biocathode covered with graphite felt (GF).Chem Eng J2016;284:1146-55

[65] Qi X,Wang Y.Development of a rapid startup method of direct electron transfer-dominant methanogenic microbial electrosynthesis.Bioresour Technol2022;358:127385

[66] Tian S,Song TS,Xie J.Artificial electron mediator with nanocubic architecture highly promotes microbial electrosynthesis from carbon dioxide.ACS Sustain Chem Eng2020;8:6777-85

[67] Aryal N,Tremblay PL,Zhang T.Enhanced microbial electrosynthesis with three-dimensional graphene functionalized cathodes fabricated via solvothermal synthesis.Electrochim Acta2016;217:117-22

[68] Hu N,Liao M.Research on electrocatalytic reduction of CO₂ by microorganisms with a graphene modified carbon felt.Int J Hydrogen Energy2021;46:6180-7

[69] Carrillo-peña D,Morán A.Reduced graphene oxide improves the performance of a methanogenic biocathode.Fuel2022;321:123957

[70] Kou T,Yao B.Interpenetrated bacteria-carbon nanotubes film for microbial fuel cells.Small Methods2018;2:1800152

[71] Yu L,Tang J.Thermophilic moorella thermoautotrophica-immobilized cathode enhanced microbial electrosynthesis of acetate and formate from CO₂.Bioelectrochemistry2017;117:23-8

[72] Peng L,Ding J.Denitrifying anaerobic methane oxidation and anammox process in a membrane aerated membrane bioreactor: kinetic evaluation and optimization.Environ Sci Technol2020;54:6968-77

[73] Wu Y,Wang L.Enhancing the selective synthesis of butyrate in microbial electrosynthesis system by gas diffusion membrane composite biocathode.Chemosphere2022;308:136088

[74] Antolini E.Composite materials for polymer electrolyte membrane microbial fuel cells.Biosens Bioelectron2015;69:54-70

[75] Li Q,Kobayashi H.GO/PEDOT modified biocathodes promoting CO₂ reduction to CH₄ in microbial electrosynthesis.Sustain Energy Fuels2020;4:2987-97

[76] Sui ZY.Effect of surface chemistry and textural properties on carbon dioxide uptake in hydrothermally reduced graphene oxide.Carbon2015;82:590-8

[77] Zeng W,Lin S.Defect-engineered reduced graphene oxide sheets with high electric conductivity and controlled thermal conductivity for soft and flexible wearable thermoelectric generators.Nano Energy2018;54:163-74

[78] Chen Z,Hao W,Cheng HM.Synthesis and applications of three-dimensional graphene network structures.Mater Today Nano2019;5:100027

[79] Mubarak S,Byun HS.Recent advances in 3D printed electrode materials for electrochemical energy storage devices.J Energy Chem2023;81:272-312

[80] Bose A,Vidoudez C,Girguis PR.Electron uptake by iron-oxidizing phototrophic bacteria.Nat Commun2014;5:3391

[81] Li S,Jae J,Jeon BH.Solid neutral red/Nafion conductive layer on carbon felt electrode enhances acetate production from CO₂ and energy efficiency in microbial electrosynthesis system.Bioresour Technol2022;363:127983

[82] Jiang YJ,Jiang LP.Functional nanomaterial-modified anodes in microbial fuel cells: advances and perspectives.Chemistry2023;29:e202202002

[83] Luo H,Zhou M.Enhanced electron transfer on microbial electrosynthesis biocathode by polypyrrole-coated acetogens.Bioresour Technol2020;309:123322

[84] Lees EW,Parlane FGL.Gas diffusion electrodes and membranes for CO₂ reduction electrolysers.Nat Rev Mater2022;7:55-64

[85] Bajracharya S,Buisman CJ,Strik DP.Application of gas diffusion biocathode in microbial electrosynthesis from carbon dioxide.Environ Sci Pollut Res Int2016;23:22292-308

[86] Dessì P,Martínez-Sosa S.Microbial electrosynthesis of acetate from CO₂ in three-chamber cells with gas diffusion biocathode under moderate saline conditions.Environ Sci Ecotechnol2023;16:100261 PMCID:PMC10120373

[87] Zhao CE,Song R,Zhang J.Nanostructured material-based biofuel cells: recent advances and future prospects.Chem Soc Rev2017;46:1545-64

[88] Nie Y,Wei Z.Recent advancements in Pt and Pt-free catalysts for oxygen reduction reaction.Chem Soc Rev2015;44:2168-201

[89] Zhu Y.Nanocarbon-based metal-free and non-precious metal bifunctional electrocatalysts for oxygen reduction and oxygen evolution reactions.J Energy Chem2021;58:610-28

[90] Jiang Y,Zhang W.Zinc: a promising material for electrocatalyst-assisted microbial electrosynthesis of carboxylic acids from carbon dioxide.Water Res2019;159:87-94

[91] Vidales A, Bruant G, Omanovic S, Tartakovsky B. Carbon dioxide conversion to C1 - C2 compounds in a microbial electrosynthesis cell with in situ electrodeposition of nickel and iron.Electrochim Acta2021;383:138349

[92] Zhang Y,Zhao C.Multicarbons generation factory: CuO/Ni single atoms tandem catalyst for boosting the productivity of CO₂ electrocatalysis.Sci Bull2022;67:1679-87

[93] Huang J,Oveisi E,Buonsanti R.Structural sensitivities in bimetallic catalysts for electrochemical CO₂ reduction revealed by Ag-Cu nanodimers.J Am Chem Soc2019;141:2490-9

[94] Chen C,Yu S.Cu-Ag tandem catalysts for high-rate CO₂ electrolysis toward multicarbons.Joule2020;4:1688-99

[95] Baek G,Rossi R.Using copper-based biocathodes to improve carbon dioxide conversion efficiency into methane in microbial methanogenesis cells.Chem Eng J2022;435:135076

[96] Zhu X,Bhatti M.Impact of metallic nanoparticles on anaerobic digestion: a systematic review.Sci Total Environ2021;757:143747

[97] Gao Y,Cai J.Metal nanoparticles increased the lag period and shaped the microbial community in slurry-electrode microbial electrosynthesis.Sci Total Environ2022;838:156008

[98] Srikanth S,Vanbroekhoven K.Electro-biocatalytic conversion of carbon dioxide to alcohols using gas diffusion electrode.Bioresour Technol2018;265:45-51

[99] Kim HW,Shin JH.Advanced control for photoautotrophic growth and CO₂-utilization efficiency using a membrane carbonation photobioreactor (MCPBR).Environ Sci Technol2011;45:5032-8

[100] Katuri KP,Jimenez-Sandoval RJ.A novel anaerobic electrochemical membrane bioreactor (AnEMBR) with conductive hollow-fiber membrane for treatment of low-organic strength solutions.Environ Sci Technol2014;48:12833-41

[101] Bian B,Katuri KP.Porous nickel hollow fiber cathodes coated with CNTs for efficient microbial electrosynthesis of acetate from CO₂ using Sporomusa ovata.J Mater Chem A2018;6:17201-11

[102] Bian B,Rabaey K.Nickel-coated ceramic hollow fiber cathode for fast enrichment of chemolithoautotrophs and efficient reduction of CO₂ in microbial electrosynthesis.Chem Eng J2022;450:138230

[103] Bian B,Katuri KP.Resistance assessment of microbial electrosynthesis for biochemical production to changes in delivery methods and CO₂ flow rates.Bioresour Technol2021;319:124177

[104] Asimakopoulos K,Skiadas IV.Reactor systems for syngas fermentation processes: a review.Chem Eng J2018;348:732-44

[105] Haas T,Weber R,Schmid G.Technical photosynthesis involving CO₂ electrolysis and fermentation.Nat Catal2018;1:32-9

[106] Claassens NJ,Kopljar D.Making quantitative sense of electromicrobial production.Nat Catal2019;2:437-47

[107] Huang Y.An integrated electrochemical and biochemical system for sequential reduction of CO₂ to methane.Fuel2018;220:8-13

[108] Yang Y,Han D,Wang G.Progress in developing metal oxide nanomaterials for photoelectrochemical water splitting.Adv Energy Mater2017;7:1700555

[109] Cui M,Zhang T,Russell TP.Three-dimensional hierarchical metal oxide-carbon electrode materials for highly efficient microbial electrosynthesis.Sustain Energy Fuels2017;1:1171-6

[110] Tahir K,Jang J,Lee DS.Enhanced product selectivity in the microbial electrosynthesis of butyrate using a nickel ferrite-coated biocathode.Environ Res2021;196:110907

[111] Wang L,Li J.Synthesis and characterization of CuFe₂O₄ nano/submicron wire-carbon nanotube composites as binder-free anodes for Li-ion batteries.ACS Appl Mater Interfaces2018;10:8770-85

[112] Thatikayala D.Copper ferrite supported reduced graphene oxide as cathode materials to enhance microbial electrosynthesis of volatile fatty acids from CO₂.Sci Total Environ2021;768:144477

[113] Guo Y,Cao Z,Yang S.MXene derivatives for energy storage and conversions.Small Methods2023;7:e2201559

[114] Shahzad F,Hatter CB.Electromagnetic interference shielding with 2D transition metal carbides (MXenes).Science2016;353:1137-40

[115] Zhang YZ,Jiang Q.MXene hydrogels: fundamentals and applications.Chem Soc Rev2020;49:7229-51

[116] Wei Y,Soomro RA,Xu B.Advances in the synthesis of 2D MXenes.Adv Mater2021;33:e2103148

[117] Tahir K,Jang J.A novel MXene-coated biocathode for enhanced microbial electrosynthesis performance.Chem Eng J2020;381:122687

[118] Tahir K,Ghani AA,Jang J.Development of a three-dimensional macroporous sponge biocathode coated with carbon nanotube-MXene composite for high-performance microbial electrosynthesis systems.Bioelectrochemistry2022;146:108140

[119] Madjarov J,Paquete CM.Sporomusa ovata as catalyst for bioelectrochemical carbon dioxide reduction: a review across disciplines from microbiology to process engineering.Front Microbiol2022;13:913311 PMCID:PMC9253864

[120] Blanchet E,Rafrafi Y,Erable B.Importance of the hydrogen route in up-scaling electrosynthesis for microbial CO₂ reduction.Energy Environ Sci2015;8:3731-44

[121] Chen WF,Fujita E.Recent developments in transition metal carbides and nitrides as hydrogen evolution electrocatalysts.Chem Commun2013;49:8896-909

[122] Zou X.Noble metal-free hydrogen evolution catalysts for water splitting.Chem Soc Rev2015;44:5148-80

[123] Tian S,Dong Z.Mo₂C-induced hydrogen production enhances microbial electrosynthesis of acetate from CO₂ reduction.Biotechnol Biofuels2019;12:71 PMCID:PMC6442412

[124] Kracke F,Maegaard K.Robust and biocompatible catalysts for efficient hydrogen-driven microbial electrosynthesis.Commun Chem2019;2:45

[125] Song T,Wan N,Xie J.Hydrothermal synthesis of MoS₂ nanoflowers for an efficient microbial electrosynthesis of acetate from CO₂.J CO2 Util2020;41:101231

[126] Zhu X,Leininger A.Syngas mediated microbial electrosynthesis for CO₂ to acetate conversion using clostridium ljungdahlii.Resour Conserv Recycl2022;184:106395

[127] Ramkumar R.Fabrication of ultrathin CoMoO₄ nanosheets modified with chitosan and their improved performance in energy storage device.Dalton Trans2015;44:6158-68

[128] Hindatu Y,Gumel A.Mini-review: anode modification for improved performance of microbial fuel cell.Renew Sustain Energy Rev2017;73:236-48

[129] Aryal N,Overgaard MH.Increased carbon dioxide reduction to acetate in a microbial electrosynthesis reactor with a reduced graphene oxide-coated copper foam composite cathode.Bioelectrochemistry2019;128:83-93

[130] Bajracharya S,Dominguez Benetton X.Carbon dioxide reduction by mixed and pure cultures in microbial electrosynthesis using an assembly of graphite felt and stainless steel as a cathode.Bioresour Technol2015;195:14-24

[131] Tharak A.Electrotrophy of biocathodes regulates microbial-electro-catalyzation of CO₂ to fatty acids in single chambered system.Bioresour Technol2021;320:124272

[132] Shakeel S.Enhanced production and utilization of biosynthesized acetate using a packed-fluidized bed cathode based MES system.J Environ Chem Eng2022;10:108067

[133] Fu Q,Li Z.Direct CO₂ delivery with hollow stainless steel/graphene foam electrode for enhanced methane production in microbial electrosynthesis.Energy Convers Manag2022;268:116018

[134] Hu N,Liao M.Research on the electrocatalytic reduction of CO₂ by microorganisms with a nano-titanium carburizing electrode.Bioelectrochemistry2021;137:107672

[135] Byrne JM,Pearce C,Appel E.Redox cycling of Fe(II) and Fe(III) in magnetite by Fe-metabolizing bacteria.Science2015;347:1473-6

[136] Zhu H,Huang Q,Xie J.Fe₃O₄/granular activated carbon as an efficient three-dimensional electrode to enhance the microbial electrosynthesis of acetate from CO₂.RSC Adv2019;9:34095-101 PMCID:PMC9073640

[137] He Y,Li J.Magnetic assembling GO/Fe₃O₄/microbes as hybridized biofilms for enhanced methane production in microbial electrosynthesis.Renew Energy2022;185:862-70

[138] Cheng J,Li H.Enhancing extracellular electron transfer of Geobacter sulfurreducens in bioelectrochemical systems using N-doped Fe₃O₄ @carbon dots.ACS Sustain Chem Eng2022;10:3935-50

[139] Thatikayala D,Min B.MnO₂/reduced graphene oxide nanohybrids as a cathode catalyst for the microbial reduction of CO₂ to acetate and isobutyric acid.Sustain Energy Technol Assess2021;45:101114

[140] Anwer AH,Khan MD,Khan MZ.High capacitive rGO/WO₃ supported nanofibers as cathode catalyst to boost-up the CO₂ sequestration via microbial electrosynthesis.J Environ Chem Eng2021;9:106650

[141] Barham JP.Synthetic photoelectrochemistry.Angew Chem Int Ed2020;59:11732-47 PMCID:PMC7383880

[142] Wang Q.Advances and challenges in developing cocatalysts for photocatalytic conversion of carbon dioxide to fuels.Nano Res2022;15:10090-109

[143] Fang X,Reisner E.Semi-biological approaches to solar-to-chemical conversion.Chem Soc Rev2020;49:4926-52

[144] Nelson N.The complex architecture of oxygenic photosynthesis.Nat Rev Mol Cell Biol2004;5:971-82

[145] Zhu XG,Ort DR.Improving photosynthetic efficiency for greater yield.Annu Rev Plant Biol2010;61:235-61

[146] Liu C,Sakimoto KK.Nanowire-bacteria hybrids for unassisted solar carbon dioxide fixation to value-added chemicals.Nano Lett2015;15:3634-9 PMCID:PMC5812269

[147] Su Y,Kim JM.Close-packed nanowire-bacteria hybrids for efficient solar-driven CO₂ fixation.Joule2020;4:800-11

[148] Nichols EM,Liu C.Hybrid bioinorganic approach to solar-to-chemical conversion.Proc Natl Acad Sci USA2015;112:11461-6 PMCID:PMC4577177

[149] Zanardo D,Tieuli S.Effects of SiO₂-based scaffolds in TiO₂ photocatalyzed CO₂ reduction.Catal Today2022;387:54-60

[150] Li J.Semiconductor-based photocatalysts and photoelectrochemical cells for solar fuel generation: a review.Catal Sci Technol2015;5:1360-84

[151] Anwer AH,Mashkoor F.Simultaneous reduction of carbon dioxide and energy harvesting using RGO-based SiO₂-TiO₂ nanocomposite for supercapacitor and microbial electrosynthesis.Appl Catal B Environ2023;339:123091

[152] Low J,Jaroniec M,Al-Ghamdi AA.Heterojunction photocatalysts.Adv Mater2017;29:1601694

[153] Xie M,Jing L,Feng Y.Long-lived, visible-light-excited charge carriers of TiO₂/BiVO₄ nanocomposites and their unexpected photoactivity for water splitting.Adv Energy Mater2014;4:1300995

[154] Wang M,Lin Z,Xie K.p-n Heterojunction photoelectrodes composed of Cu₂O-loaded TiO₂ nanotube arrays with enhanced photoelectrochemical and photoelectrocatalytic activities.Energy Environ Sci2013;6:1211-20

[155] Yu J,Xiao W,Jaroniec M.Enhanced photocatalytic CO₂-reduction activity of anatase TiO₂ by coexposed {001} and {101} facets.J Am Chem Soc2014;136:8839-42

[156] Song TS,Tao R,Xie J.CuO/g-C₃N₄ heterojunction photocathode enhances the microbial electrosynthesis of acetate through CO₂ reduction.Sci Total Environ2022;818:151820

[157] Li T,Luo D,Xie J.CuO/g-C₃N₄/rGO multifunctional photocathode with simultaneous enhancement of electron transfer and substrate mass transfer facilitates microbial electrosynthesis of acetate.Int J Hydrogen Energy2022;47:34875-86

[158] Barber J.Photosynthetic energy conversion: natural and artificial.Chem Soc Rev2009;38:185-96

[159] Nozik AJ.p-n photoelectrolysis cells.Appl Phys Lett1976;29:150-3

[160] Liu C,Yang P.Semiconductor nanowires for artificial photosynthesis.Chem Mater2014;26:415-22

[161] Huang D,Zeng G.Artificial Z-scheme photocatalytic system: what have been done and where to go?.Coord Chem Rev2019;385:44-80

[162] Cai Z,Quan X,Shi Y.Acetate production from inorganic carbon (HCO₃^-) in photo-assisted biocathode microbial electrosynthesis systems using WO₃/MoO₃/g-C₃N₄ heterojunctions and Serratia marcescens species.Appl Catal B2020;267:118611

[163] Huang L,Cai Z,Li Puma G.Efficient conversion of bicarbonate (HCO₃^-) to acetate and simultaneous heavy metal Cr(VI) removal in photo-assisted microbial electrosynthesis systems combining WO₃/MoO₃/g-C₃N₄ heterojunctions and Serratia marcescens electrotroph.Chem Eng J2021;406:126786

[164] Kong W,Quan X,Li Puma G.Efficient production of acetate from inorganic carbon (HCO₃^-) in microbial electrosynthesis systems incorporating Ag₃PO₄/g-C₃N₄ anaerobic photo-assisted biocathodes.Appl Catal B2021;284:119696

[165] Huang L,Shi Y,Li Puma G.Cellular electron transfer in anaerobic photo-assisted biocathode microbial electrosynthesis systems for acetate production from inorganic carbon (HCO₃^-).Chem Eng J2022;431:134022

[166] Li T,Song T.α-Fe₂O₃/g-C₃N₄ Z-scheme heterojunction photocathode to enhance microbial electrosynthesis of acetate from CO₂.ACS Sustain Chem Eng2022;10:17308-17

[167] Kong W,Quan X.Synergistic induced charge transfer switch by oxygen vacancy and pyrrolic nitrogen in MnFe₂O₄/g-C₃N₄ heterojunctions for efficient transformation of bicarbonate to acetate in photo-assisted MES.Appl Catal B2022;307:121214

[168] You S,Wang W.3D macroporous nitrogen-enriched graphitic carbon scaffold for efficient bioelectricity generation in microbial fuel cells.Adv Energy Mater2017;7:1601364

[169] Lau VW,Ehrat F.Urea-modified carbon nitrides: enhancing photocatalytic hydrogen evolution by rational defect engineering.Adv Energy Mater2017;7:1602251

[170] Yu W,Zeng Y.Solar-driven producing of value-added chemicals with organic semiconductor-bacteria biohybrid system.Research2022;2022:9834093 PMCID:PMC8972406

[171] Vassilev I,Puig S.Cathodic biofilms - a prerequisite for microbial electrosynthesis.Bioresour Technol2022;348:126788

[172] Yu SS,Liu XY.Interfacial electron transfer from the outer membrane cytochrome OmcA to graphene oxide in a microbial fuel cell: spectral and electrochemical insights.ACS Energy Lett2018;3:2449-56

[173] Thapa BS,Pandit S.Overview of electroactive microorganisms and electron transfer mechanisms in microbial electrochemistry.Bioresour Technol2022;347:126579

[174] Xia Q,Chen X,Zhu JJ.In vivo voltammetric imaging of metal nanoparticle-catalyzed single-cell electron transfer by fermi level-responsive graphene.Research2023;6:0145 PMCID:PMC10200910

[175] Li F,Cao YX.Modular engineering to increase intracellular NAD(H/⁺) promotes rate of extracellular electron transfer of Shewanella oneidensis.Nat Commun2018;9:3637 PMCID:PMC6128845

[176] Li F,Zhang B.Systematic full-cycle engineering microbial biofilms to boost electricity production in shewanella oneidensis.Research2023;6:0081 PMCID:PMC10017123

[177] Yang HY,Wang YX.Mixed-culture biocathodes for acetate production from CO₂ reduction in the microbial electrosynthesis: impact of temperature.Sci Total Environ2021;790:148128

[178] Guo F,Beyenal H.The effect of additional salinity on performance of a phosphate buffer saline buffered three-electrode bioelectrochemical system inoculated with wastewater.Bioresour Technol2021;320:124291

[179] Li X,Lu Y,Luo H.Development of methanogens within cathodic biofilm in the single-chamber microbial electrolysis cell.Bioresour Technol2019;274:403-9

[180] Wang H,Zeng S.Explore the difference between the single-chamber and dual-chamber microbial electrosynthesis for biogas production performance.Bioelectrochemistry2021;138:107726