Oct 2024, Volume 30 Issue 1
    

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  • Zhiyong Zhao, Shuai Yue, Gaohua Yang, Pengfei Wang, Sihui Zhan

    With the rapid development of plastic production and consumption globally, the amount of post-consumer plastic waste has reached levels that have posed environmental threats. Considering the substantial CO2 emissions throughout the plastic lifecycle from material production to its disposal, photocatalysis is considered a promising strategy for effective plastic recycling and upcycling. It can upgrade plastics into value-added products under mild conditions using solar energy, realizing zero carbon emissions. In this paper, we explain the basics of photocatalytic plastic reformation and underscores plastic feedstock reformation pathways into high-value-added products, including both degradation into CO2 followed by reformation and direct reformation into high-value-added products. Finally, the current applications of transforming plastic waste into fuels, chemicals, and carbon materials and the outlook on upcycling plastic waste by photocatalysis are presented, facilitating the realization of carbon neutrality and zero plastic waste.

  • Chuan Li, Rong Zhang, Huilin Cui, Yanbo Wang, Guojin Liang, Chunyi Zhi

    Recently, rechargeable aqueous zinc-based batteries using manganese oxide as the cathode (e.g., MnO2) have gained attention due to their inherent safety, environmental friendliness, and low cost. Despite their potential, achieving high energy density in Zn||MnO2 batteries remains challenging, highlighting the need to understand the electrochemical reaction mechanisms underlying these batteries more deeply and optimize battery components, including electrodes and electrolytes. This review comprehensively summarizes the latest advancements for understanding the electrochemistry reaction mechanisms and designing electrodes and electrolytes for Zn||MnO2 batteries in mildly and strongly acidic environments. Furthermore, we highlight the key challenges hindering the extensive application of Zn||MnO2 batteries, including high-voltage requirements and areal capacity, and propose innovative solutions to overcome these challenges. We suggest that MnO2/Mn2+ conversion in neutral electrolytes is a crucial aspect that needs to be addressed to achieve high-performance Zn||MnO2 batteries. These approaches could lead to breakthroughs in the future development of Zn||MnO2 batteries, offering a more sustainable, cost-effective, and high-performance alternative to traditional batteries.

  • Runnan Zou, Yanhong Tong, Jiayi Liu, Jing Sun, Da Xian, Qingxin Tang

    Recently, electronic skins and flexible wearable devices have been developed for widespread applications in medical monitoring, artificial intelligence, human–machine interaction, and artificial prosthetics. Flexible proximity sensors can accurately perceive external objects without contact, introducing a new way to achieve an ultrasensitive perception of objects. This article reviews the progress of flexible capacitive proximity sensors, flexible triboelectric proximity sensors, and flexible gate-enhanced proximity sensors, focusing on their applications in the electronic skin field. Herein, their working mechanism, materials, preparation methods, and research progress are discussed in detail. Finally, we summarize the future challenges in developing flexible proximity sensors.

  • Yu-Long Men, Ning Dou, Yiyi Zhao, Yan Huang, Lei Zhang, Peng Liu

    Electrocatalytic glucose oxidation reaction (GOR) has attracted much attention owing to its crucial role in biofuel cell fabrication. Herein, we load MoO3 nanoparticles on carbon nanotubes (CNTs) and use a discharge process to prepare a noble-metal-free MC-60 catalyst containing MoO3, Mo2C, and a Mo2C–MoO3 interface. In the GOR, MC-60 shows activity as high as 745 µA/(mmol/L cm2), considerably higher than those of the Pt/CNT (270 µA/(mmol/L cm2)) and Au/CNT catalysts (110 µA/(mmol/L cm2)). In the GOR, the response minimum on MC-60 is as low as 8 µmol/L, with a steady-state response time of only 3 s. Moreover, MC-60 has superior stability and anti-interference ability to impurities in the GOR. The better performance of MC-60 in the GOR is attributed to the abundant Mo sites bonding to C and O atoms at the MoO3–Mo2C interface. These Mo sites create active sites for promoting glucose adsorption and oxidation, enhancing MC-60 performance in the GOR. Thus, these results help to fabricate more efficient noble-metal-free catalysts for the fabrication of glucose-based biofuel cells.

  • Xiaoyun Sun, Deren Wang, Haochen Hu, Xin Wei, Lin Meng, Zhongshan Ren, Sensen Li

    Ensuring a stable power output from renewable energy sources, such as wind and solar energy, depends on the development of large-scale and long-duration energy storage devices. Zinc–bromine flow batteries (ZBFBs) have emerged as cost-effective and high-energy-density solutions, replacing expensive all-vanadium flow batteries. However, uneven Zn deposition during charging results in the formation of problematic Zn dendrites, leading to mass transport polarization and self-discharge. Stable Zn plating and stripping are essential for the successful operation of high-areal-capacity ZBFBs. In this study, we successfully synthesized nitrogen and oxygen co-doped functional carbon felt (NOCF4) electrode through the oxidative polymerization of dopamine, followed by calcination under ambient conditions. The NOCF4 electrode effectively facilitates efficient “shuttle deposition” of Zn during charging, significantly enhancing the areal capacity of the electrode. Remarkably, ZBFBs utilizing NOCF4 as the anode material exhibited stable cycling performance for 40 cycles (approximately 240 h) at an areal capacity of 60 mA h/cm2. Even at a high areal capacity of 130 mA h/cm2, an impressive energy efficiency of 76.98% was achieved. These findings provide a promising pathway for the development of high-areal-capacity ZBFBs for advanced energy storage systems.

  • Xincheng Li, Yunhao Liu, Dejian Zhao, Shuaishuai Lyu, Jingwei Ye, Xiaoshen Li, Peipei Wu, Ye Tian, Yingtian Zhang, Tong Ding, Song Song, Qingpeng Cheng, Xingang Li

    Nitrogen (N)-doped carbon materials as metal catalyst supports have attracted significant attention, but the effect of N dopants on catalytic performance remains unclear, especially for complex reaction processes such as Fischer–Tropsch synthesis (FTS). Herein, we engineered ruthenium (Ru) FTS catalysts supported on N-doped carbon overlayers on TiO2 nanoparticles. By regulating the carbonization temperatures, we successfully controlled the types and contents of N dopants to identify their impacts on metal–support interactions (MSI). Our findings revealed that N dopants establish a favorable surface environment for electron transfer from the support to the Ru species. Moreover, pyridinic N demonstrates the highest electron-donating ability, followed by pyrrolic N and graphitic N. In addition to realizing excellent catalytic stability, strengthening the interaction between Ru sites and N dopants increases the Ru0/Ru δ+ ratios to enlarge the active site numbers and surface electron density of Ru species to enhance the strength of adsorbed CO. Consequently, it improves the catalyst’s overall performance, encompassing intrinsic and apparent activities, as well as its ability for carbon chain growth. Accordingly, the as-synthesized Ru/TiO2@CN-700 catalyst with abundant pyridine N dopants exhibits a superhigh C5+ time yield of 219.4 molCO/(molRu·h) and C5+ selectivity of 85.5%.