Visible-light-responsive mesoporous PtO/2D YVO4 composite material for fostered photocatalytic hydrogen generation

Abstract

Hydrogen (H2) is a significant alternative energy supply due to its outstanding and potentially useful properties, promoting sustainable development. Photocatalytic H2 generation from H2O employing inexhaustible and naturally abundant solar power on semiconducting photocatalysts is a promising and sustainable approach. Yet, particle aggregation/agglomeration, insufficient solar-light absorbance capacity, and quick photo-excited charge carriers’ recombination are the main deficiencies in most current photocatalytic systems. This investigation intends to fabricate mesoporous YVO4 nanosheets through a facile hydrothermal process, employing polyvinyl alcohol polymer as a structural directing agent to prevent agglomeration. Moreover, for the first time, varied tiny contents of platinum oxide (PtO) ranging from 0.3 to 1.2 wt%, were decorated on YVO4, constructing p-n PtO-YVO4 heterojunctions. The fabricated catalysts were characterized via advanced instruments and applied to H2 production using visible light energy. It was found that the physicochemical characteristics of the designed catalysts revealed the influence of loading PtO on the surface, structure, light absorbance features, charge separation, and efficacy. The loading of 0.9 wt% PtO on YVO4 has barely lowered the surface area (SA) from 187 to 176 m2/g. In contrast, the visible wavelength uptake is notably extended owing to the substantial energy bandgap narrowing from 3.40 to 2.11 eV. The visible-light-evolved hydrogen on 0.9 wt% PtO-YVO4 amounted to 34.76 mmol g−1. Moreover, this novel sample demonstrated a 99.88% recycling capacity after five cycles. This efficacious photocatalytic H2 generation is due to extensive light sensitivity and the rapid charge separation and migration between PtO and YVO4 following the p-n heterojunction mechanism.