Photocatalytic hydrogen evolution from water has triggered an intensive search for metal-free semiconducting photocatalysts. However, traditional semiconducting materials suffer from limited hydrogen evolution efficiency owing to low intrinsic electron transfer, rapid recombination of photogenerated carriers, and lack of artificial microstructure. Herein, we report a metal-free half-metallic carbon nitride for highly efficient photocatalytic hydrogen evolution. The introduced half-metallic features not only effectively facilitate carrier transfer but also provide more active sites for hydrogen evolution reaction. The nanosheets incorporated into a micro grid mode resonance structure via in situ pyrolysis of ionic liquid, which show further enhanced photoelectronic coupling and entire solar energy exploitation, boosts the hydrogen evolution rate reach up to 1009 μmol g−1 h−1. Our findings propose a strategy for micro-structural regulations of half-metallic carbon nitride material, and meanwhile the fundamentals provide inspirations for the steering of electron transfer and solar energy absorption in electrocatalysis, photoelectrocatalysis, and photovoltaic cells.

Figure 1. TEM images of GO (a) and GQDs (b). The inset of (b) shows the size distribution of GQDs with a probable size of 8.3 nm. wileyonlinelibrary.com

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Graphene was synthesized by chemical vapor deposition using polystyrene as the solid carbon source. The number of graphene layers could be controlled by regulating the weight of polystyrene under atmospheric pressure at 1000 °C. Silver nanoparticles were then deposited on the graphene by a citrate reduction method. The interaction between graphene and silver was investigated by suface-enhanced Raman scattering spectra and X-ray photoelectron spectroscopy. The change in the G band position indicates n-type doping of the graphene due to an interaction between the silver and the graphene. Silver interlayer doped four-layer graphene shows a sheet resistance of 63 Ω/sq and a light transmittance of 85.4% at 550 nm. The optical and electrical quality of graphene exceeds the minimum industry standard for indium tin oxide replacement materials. It is clearly understood that the environmental sheet resistance stability of the interlayer doped graphene film is better than that of surface doped graphene sheets. The presence of graphene at the surface also acts as a protective layer for the inner silver ions and clusters.

The future of sustainable energy supply demands innovative breakthroughs in the design of cheap and durable catalysts for efficient electrochemical water splitting. Distinct from the conventional doping, defecting, and nanostructuring strategy, we develop a simple and feasible electric-strain way to trigger electrocatalyst's structural phase transition via regulating carrier distribution, realizing an excellent hydrogen evolution reaction (HER) performance. Herein, thanks to the intrinsic noncentrosymmetric polarization of our designed Janus MoReS 3 nanostructures, large numbers of carriers are energetically pulled into the catalyst's interior to generate electric strain, leading to the deformation of the charged MoReS 3 nanosheets and transition from T 0 phase to another reversible atomic configuration (T 00 phase) with higher catalytic activity and faster carrier transfer. The electric-strain-generated T 00-MoReS 3 shows HER performances in excess of a commercial Pt/C electrode at large current densities, reaching a current density of 150 mA cm À2 at an overpotential of 189 mV.

The future of sustainable fertilizers and carbon-free energy carrier demands innovative breakthroughs in the exploitation of efficient electrocatalysts for synthesizing ammonia (NH3) from nitrogen (N2) in mild conditions. Understanding and regulating the reaction intermediates that form on the catalyst surface through careful catalyst design could bypass certain limitations associated with ambiguous adsorbate evolution mechanism. Herein, we propose ternary intermetallic Re2MnS6 ultrathin nanosheets that include orderly hybridized Mn–Re dual-metal sites through strong Hubbard e-e interaction, demonstrating a promising selectivity toward reaction process from N2 to NH3. The ordered inclusion of Mn sites leads to a structural phase transition and appearance of nonbonding semimetal states, in which the rate-limiting activation energy barrier is significantly decreased through a conversion in reaction pathway. As a result, the performance of N2 reduction in Re2MnS6 is increased about 6.6 times compared to the single-metal ReS2.

Perovskite-based optoelectronic devices have shown great promise for solar conversion and other optoelectronic applications, but their long-term performance instability is regarded as a major obstacle to their widespread deployment. Previous works have shown that the ultralow thermal conductivity and inefficient heat spreading might put an intrinsic limit on the lifetime of perovskite devices. Here, we report the observation of a remarkably efficient thermal conductance, with a conductivity of 11.2 ± 0.8 W m−1 K−1 at room temperature, in densely packed perovskite CH3NH3PbI3 films, via noncontact time-domain thermal reflectance measurements. The temperature-dependent experiments suggest the important roles of organic cations and structural phase transitions, which are further confirmed by temperature-dependent Raman spectra. The thermal conductivity at room temperature observed here is over one order of magnitude larger than that in the early report, suggesting that perovskite device performance will not be limited by thermal conductance.

In confined space with length scale of several nanometers, the phase behavior of matter, e.g., nucleation and crystallization, is completely different from its analogue in bulk. However, in environmental applications, the relationship between the nanoconfined crystallization behavior of inorganic crystals and their properties for pollutant removal is rarely elucidated. Herein, an unusual formation of zirconium phosphate (ZrP) crystals as a mixture of both thermodynamically stable α‐ and metastable γ‐phases inside the nanoconfinement of 7.9 nm pores of mesoporous polystyrene (MPS) is reported. This consequently changes the interaction between ZrP and toxic metal cations from nonspecific electrostatic attraction of normal α‐ZrP to highly specific inner‐sphere coordination of nanoconfined γ‐ZrP, which exhibits remarkable reactivity as well as reusability for the removal of toxic metals. The results of this study contribute to a better understanding of the use of nanoconfinement for the regulation of material properties.