Engineering Nanoscale Homo–Heterojunction for Robust Z‐Scheme CO₂ Conversion through Synchronous Amalgamation of Oxygen‐Defective Ultrathin BiVO₄ and Red/Black Phosphorus

Abstract

Sunlight‐driven CO2 conversion into value‐added fuels emerges as an avant‐garde strategy to mitigate the imminent energy scarcity and global warming. Nevertheless, sluggish charge kinetics and rapid carrier recombination are deemed as the foremost bottlenecks of efficient CO2 photoreduction. In this contribution, the aforementioned shortcomings are addressed by assembling a homo–hetero architecture comprising oxygen‐defective ultrathin BiVO4 (BiVO4–Ov) and red/black phosphorus (RP/BP) homojunction with a built‐in nanoscale dual Z‐scheme electronic configuration. The development of BiVO4–Ov@RP/BP confers two electron relaying channels, that is, one from the RP/BP homojunction and another from the BiVO4–Ov/RP heterojunction, which warrant the efficient separation of electron–hole pairs. Besides, the ultrathin 2D and oxygen vacant nature of BiVO4–Ov exposes more active sites and renders electron trapping for efficient utilization of photogenerated charges. Amalgamating the desirable properties, the meticulously developed dual Z‐scheme homo–heterojunction system on the basis of surface defect‐engineered ultrathin BiVO4–Ov nanosheets integrated with RP/BP offers a new avenue for the exploration, design, and fabrication of new generation photocatalysts with exceptional photocatalytic activities. In particular, the BiVO4–Ov@RP/BP system demonstrates a remarkably high CH4 yield of 14.52 μmol g−1 after 6 h of visible light illumination, which resembles a leading‐edge photocatalytic performance among the existing BiVO4‐ and P‐based semiconductors.

Enhanced Catalytic Activity of Crystalline Phosphorus Nanosheets Fabricated via Solvothermal Phase Transformation

“…Solvothermal approach, a broadly employed synthesis technique, manufactures massive amounts of commercial products in a safe and reliable manner. Therefore, the solvothermal synthesis of phosphorus was enthusiastically embraced once reported, producing numerous allotropes such as amorphous and crystalline red phosphorus (RP), − BP, , and BP/RP heterophase junction, , which are suitable for energetic, ,, environmental, therapeutic, sensing, photothermoelectric, and catalytic applications. − However, due to the complicated phosphorus–solvent interactions and unconfirmed molecular structures of certain allotropes, the crystallization of solvothermally synthesized P remains a “black box,” with the mechanism(s) yet to be revealed. This undoubtedly hinders the a priori design and property upgrade of these materials.…”