Graphitic carbon nitride (g-C3N4) has attracted extensive research attention because of its virtues of a metal-free nature, feasible synthesis, and excellent properties. However, the low specific surface area and mediocre charge separation dramatically limit the practical applications of g-C3N4. Herein, porous nitrogen defective g-C3N4 (PDCN) was successfully fabricated by the integration of urea-assisted supramolecular assembly with the polymerization process. Advanced characterization results suggested that PDCN exhibited a much larger specific surface area and dramatically improved charge separation compared to bulk g-C3N4, leading to the formation of more active sites and the improvement in mass transfer. The synthesized PDCN rendered a 16-fold increase in photocatalytic tetracycline degradation efficiency compared to g-C3N4. Additionally, the hydrogen evolution rate of PDCN was 10.2 times higher than that of g-C3N4. Meanwhile, the quenching experiments and electron spin resonance (ESR) spectra suggested that the superoxide radicals and holes are the predominant reactive species for the photocatalytic degradation process. This study may inspire the new construction design of efficient g-C3N4-based visible-light photocatalysts.

Solar energy‐induced catalysis has been attracting intensive interests and its quantum efficiencies in plasmon‐mediated photothermal catalysis (P‐photothermal catalysis) and external heat‐coupled photocatalysis (E‐photothermal catalysis) are ultimately determined by the catalyst structure for photo‐induced energetic hot carriers. Herein, different catalysts of supported (TiO2‐P25 and Al2O3) platinum quantum dots are employed in photo, thermal, and photothermal catalytic dry reforming of methane. Integrated experimental and computational results unveil different active sites (hot zones) on the two catalysts for photo, thermal, and photothermal catalysis. The hot zones of P‐photothermal catalysis are identified to be the metal–support interface on Pt/P25 and the Pt surface on Pt/Al2O3, respectively. However, a change of the active site to the Pt surface on Pt/P25 is for the first time observed in E‐photothermal catalysis (external heating temperature of 700 °C). The hot zones contribute to the significant enhancements in photothermal catalytic reactivity against thermocatalysis. This study helps to understand the reaction mechanism of photothermal catalysis to exploit efficient catalysts for solar energy utilization and fossil fuels upgrading.

Photocatalysis plays a vital role in sustainable energy conversion and environmental remediation because of its economic, eco-friendly, and effective characteristics. Nitrogen-rich graphitic carbon nitride (g-C3N5) has received worldwide interest owing to its facile accessibility, metal-free nature, and appealing electronic band structure. This review summarizes the latest progress for g-C3N5-based photocatalysts in energy and environmental applications. It begins with the synthesis of pristine g-C3N5 materials with various topologies, followed by several engineering strategies for g-C3N5, such as elemental doping, defect engineering, and heterojunction creation. In addition, the applications in energy conversion (H2 evolution, CO2 reduction, and N2 fixation) and environmental remediation (NO purification and aqueous pollutant degradation) are discussed. Finally, a summary and some inspiring perspectives on the challenges and possibilities of g-C3N5-based materials are presented. It is believed that this review will promote the development of emerging g-C3N5-based photocatalysts for more efficiency in energy conversion and environmental remediation.

Photoreforming of lignin has been explored as a fascinating technology to generate clean hydrogen energy and value-added aromatic monomers from biomass. However, its upscaling is impeded by unsatisfactory selectivity due to the lack of mechanistic investigations in the uncontrollable reaction pathways. Herein, we successfully controlled the concentration and position of sulfur vacancies within the ultrathin ZnIn2S4 nanosheets to optimize the photo-driven lignin model reforming process. The competition of proton transfer between the hydrogen evolution and dissociation of the β-O-4 linkage in the model compound of lignin was identified, and the modulation of the proton migration pathway was realized through S vacancy engineering in ZnIn2S4 nanosheets toward target products. As such, excellent selectivity for hydrogen and chemical monomers was achieved with a high concentration of S vacancies in the bulk and on the surface of ZnIn2S4, respectively. This study endows new mechanistic insights into the biomass photoreforming process and elucidates the structure/chemistry-catalysis correlation of ZnIn2S4 photocatalysts, which are beneficial for photocatalyst design and rational solar fuel production.

Traditional synthesis approaches of bismuth nanoparticles decorated carbon nitride (C3N4) materials suffers from the complex synthesis process and the addition of surfactant, which is not conducive to environmental protection. To...