The moiré superlattice, arising from the interface of mismatched single crystals, intricately regulates the physical and mechanical properties of materials, giving rise to phenomena such as superconductivity and superlubricity. This study delves into the profound impact of moiré superlattices on the interfacial mechanical behavior of van der Waals (vdW) layered materials, with a particular focus on tribological properties. A comprehensive review of continuum modeling approaches for vdW layered materials is presented, accentuating the incorporation of moiré superlattice effects in theoretical models to unravel their distinctive interfacial frictional behavior and thermodynamic properties. The exploration of moiré superlattices has significantly advanced our fundamental understanding of interface phenomena in vdW layered materials. This progress provides crucial theoretical insights that can inform the design of multifunctional devices based on the unique properties of twisted layered materials.

Oxide semimetals exhibiting both nontrivial topological characteristics stand as exemplary parent compounds and multiple degrees of freedom, offering a promise for the realization of novel electronic states. In this work, we report the structural and transport phase transition in an oxide semimetal, SrNbO₃, achieved through effective anion doping. Notably, the resistivity increased by more than three orders of magnitude at room temperature upon nitrogendoping. The extent of electronic modulation in SrNbO₃ is strongly correlated with misfit strain, underscoring its phase instability to both chemical doping and crystallographic symmetry variations. Using first-principles calculations, we discern that elevating the level of nitrogen doping induces an upward shift in the conductive bands of SrNbO_3−δN_δ. Consequently, a transition from a metallic state to an insulating state becomes apparent as the nitrogen concentration reaches a threshold of 1/3. This investigation shows effective anion engineering in oxide semimetals, offering pathways for manipulating their physical properties.

Fullerene derivatives are highly attractive materials in solar cells, organic thermoelectrics, and other devices. However, the intrinsic low electron mobility and electrical conductivity restrict their potential device performance, such as perovskite solar cells (PSCs). Herein, we successfully enhanced the electric properties and morphology of phenyl-C₆₁-butyric acid methyl ester (PCBM) by n-doping it with a benzimidazoline derivative, 9-(1,3-dimethyl-2,3-dihydro-1H-benzoimidazol-2-yl)-julolidine (JLBI-H) via a solution process. We found the n-doping can not only improve the conductivity and optimize the band alignment but also enable the PCBM to have a constantly strong charge extraction ability in a wide temperature from 173 to 373 K, which guarantees a stable photovoltaic performance of the corresponding PSCs under a wide range of operating temperatures. With the JLBI-H-doped PCBM, we improved the efficiency from 17.9% to 19.8%, along with enhanced stability of the nonencapsulated devices following the aging protocol of ISOS-D-1.

The development of stable and efficient low-cost electrocatalysts is conducive to the industrialization of CO₂. The synergy effect between the heterogeneous interface of metal/oxide can promote the conversion of CO₂. In this work, Cu₂O/ZnO heterostructures with partially reduced metal/oxide heterointerfaces in Zn plates (CZZ) have been synthesized for CO₂ electroreduction in different cationic solutions (K⁺ and Cs⁺). Physical characterizations were used to demonstrate the heterojunction of Cu₂O/ZnO and the heterointerfaces of metal/oxide; electrochemical tests were used to illustrate the enhancement of the selectivity of CO₂ to CO in different cationic solutions. Faraday efficiency for CO with CZZ as catalyst reaches 70.9% in K⁺ solution (current density for CO −3.77 mA cm⁻² and stability 24 h), and the Faraday efficiency for CO is 55.2% in Cs⁺ solution (−2.47 mA cm⁻² and 21 h). In addition, in situ techniques are used to elucidate possible reaction mechanisms for the conversion of CO₂ to CO in K⁺ and Cs⁺ solutions.

Poly(heptazine imide) (PHI), a semicrystalline version of carbon nitride photocatalyst based on heptazine units, has gained significant attention for solar H₂ production benefiting from its advantages including molecular synthetic versatility, excellent physicochemical stability and suitable energy band structure to capture visible photons. Typically, PHI is obtained in saltmelt synthesis in the presence of alkali metal chlorides. Herein, we examined the role of binary alkali metal bromides (LiBr/NaBr) with diverse compositions and melting points to rationally modulate the polymerization process, structure, and properties of PHI. Solid characterizations revealed that semicrystalline PHI with a condensed π-conjugated system and rapid charge separation rates were obtained in the presence of LiBr/NaBr. Accordingly, the apparent quantum yield of hydrogen using the optimized PHI reaches up to 62.3% at 420 nm. The density functional theory calculation shows that the dehydrogenation of the ethylene glycol has a lower energy barrier than the dehydrogenation of the other alcohols from the thermodynamic point of view. This study holds great promise for rational modulation of the structure and properties of conjugated polymeric materials.

The contamination of nitric oxide presents a significant environmental challenge, necessitating the development of efficient photocatalysts for remediation. Conventional heterojunctions encounter obstacles such as large contact barriers, sluggish charge transport, and compromised redox capacity. Here, we introduce an innovative S-type heterostructure photocatalyst, UiO-66-NH₂/ZnS(en)_0.5, designed specifically to overcome these challenges. The synthesis, employing a unique microwave solvothermal method, strategically aligns the lowest unoccupied molecular orbital of UiO-66-NH₂ with the highest occupied molecular orbital of ZnS(en)_0.5, fostering the formation of a stepped heterojunction. The resulting intimate interface contact generates a built-in electric field, facilitating charge separation and migration, as evidenced by time-resolved photoluminescence spectroscopy and photoelectrochemical tests. The abundant active sites in the porous UiO-66-NH₂ counterpart provide adsorption and activation sites for nitrogen monoxide (NO) oxidation. Performance evaluation reveals exceptional photocatalytic NO removal, achieving 70% efficiency and 99% selectivity toward nitrates under simulated solar illumination. Evidence from X-ray photoelectron spectroscopy and trapping experiments supports the effectiveness of the S-type heterostructure, showcasing refined reactive oxygen species, particularly superoxide. Thus, this study introduces a new perspective on advanced NO oxidation and unlocks the potential of S-scheme heterojunctions to refine reactive oxygen species for NO remediation.

Conducting polymer hydrogel can address the challenges of stricken biocompatibility and durability. Nevertheless, conventional conducting polymer hydrogels are often brittle and weak due to the intrinsic quality of the material, which exhibits viscoelasticity. This property may cause a delay in sensor response time due to hysteresis. To overcome these limitations, we have designed a wrinkle morphology three-dimensional (3D) substrate using digital light processing technology and then followed by in situ polymerization to form interpenetrating polymer network hydrogels. This novel design results in a wrinkle morphology conducting polymer hydrogel elastomer with high precision and geometric freedom, as the size of the wrinkles can be controlled by adjusting the treating time. The wrinkle morphology on the conducting polymer hydrogel effectively reduces its viscoelasticity, leading to samples with quick response time, low hysteresis, stable cyclic performance, and remarkable resistance change. Simultaneously, the 3D gradient structure augmented the sensor’s sensitivity under minimal stress while exhibiting consistent sensing performance. These properties indicate the potential of the conducting polymer hydrogel as a flexible sensor.

Sodium (Na) metal is a competitive anode for next-generation energy storage applications in view of its low cost and high-energy density. However, the uncontrolled side reactions, unstable solid electrolyte interphase (SEI) and dendrite growth at the electrode/electrolyte interfaces impede the practical application of Na metal as anode. Herein, a heterogeneous Na-based alloys interfacial protective layer is constructed in situ on the surface of Na foil by self-diffusion of liquid metal at room temperature, named “HAIP Na.” The interfacial Na-based alloys layer with good electrolyte wettability and strong sodiophilicity, and assisted in the construction of NaF-rich SEI. By means of direct visualization and theoretical simulation, we verify that the interfacial Na-based alloys layer enabling uniform Na⁺ flux deposition and suppressing the dendrite growth. As a result, in the carbonate-based electrolyte, the HAIP Na||HAIP Na symmetric cells exhibit a remarkably enhanced cycling life for more than 650 h with a capacity of 1mAh cm⁻² at a current density of 1mAcm⁻². When the HAIP Na anode is paired with sulfurized polyacrylonitrile (SPAN) cathode, the SPAN||HAIP Na full cells demonstrate excellent rate performance and cycling stability.

Low efficiency and spectral instability caused by the surface defects have been considerable issues for the mixed-halogen blue emitting perovskite quantum dots light-emitting diodes (PeQLEDs). Here, an in situ surface passivation to perovskite quantum dots (PeQDs) is realized by introducing the metal cations competitive lattice occupancy assisted with acid-etching, in which the longchain, insulating and weakly bond surface ligands are removed by addition of octanoic acid (OTAC). Meanwhile, the dissolved A-site cations (Na⁺) compete with the protonated oleyl amine and are subsequently anchored to the surface vacancies. The preadded lead bromide, acting as inorganic ligands, demonstrates strong bonding to the uncoordinated surface ions. The as-synthesized PeQDs show the boosted photoluminescence quantum yield (PLQY) and superior stability with longer lifetime. As a result, the PeQLEDs (470 nm) based on the OTAC-Na PeQDs exhibit an external quantum efficiency of 8.42% in the mixed halogen PeQDs (CsPb(Br_xCl_1–x)₃). Moreover, the device exhibits superior spectra stability with negligible shift. Our competition mechanism in combination with in situ passivation strategy paves a new way for improving the performance of blue PeQLEDs.