Two-dimensional amorphous heterostructures of Ag/a-WO3-x for high-efficiency photocatalytic performance

A well-defined synergistic photocatalysis system is first realized by the 2D amorphous heterostructures (2DAHs) Ag/a-WO3-x. The superposition effect of local surface plasmon resonances (LSPR) catalysis and amorphous effect (unique d-d tail states coupling of both Ag and W atoms in the 2DAHs) catalysis can be demomstrated to lead an enhanced photoelectrochemical performance. [Display omitted] •A well-defined synergistic photocatalysis system is realized by the 2D amorphous heterostructures (2DAHs) Ag/a-WO3-x.•The as-prepared Ag(Au)/a-WO3-x systems have enhanced photoelectrochemical (PEC) performance.•DFT calculations indicate the enhanced PEC activity attributes to both amorphous effect catalysis and LSPR catalysis.•The underlying physical mechanism of the amorphous effect catalysis stems from the unique d-d tail states coupling. Synergistic photocatalysis is an important concept for designing the high-efficiency catalysis for fundamental research and technical applications. In this study a well-defined synergistic photocatalysis system is realized by the 2D amorphous heterostructures (2DAHs) Ag/a-WO3-x, which are constructed by Ag nanoparticles on 2D amorphous tungsten oxide (a-WO3-x) fabricated via supercritical CO2 method. We demonstrate theoretically that the oxygen evolution reactions (OER), characterized by photocurrent response, have been dramatically improved in Ag/a-WO3-x than those of both single a-WO3-x and Ag/WO3 systems. Such an enhanced photoelectrochemical performance attributes to the superposition effect of amorphous effect catalysis and local surface plasmon resonances (LSPR) catalysis. More interestingly, the ab inito density-functional theory calculations reveal that the amorphous effect catalysis ascribes to the unique d-d tail states coupling of both Ag and W atoms in the 2DAHs. Overall, our findings not only propose the prototype of synergistic photocatalysis, but also provide a new methodology to the design of novel catalyst.