Synthesis and photoelectrochemical catalytic properties of polyoxometalate supported on zeolitic imidazolate Framework, ZIF-9–PMo<inf>12</inf>

Development of photocatalysts for hydrogen generation is highly imperative in the current scenario for resolving the worldwide energy crisis. Continuous efforts are being made to find low-cost and durable photocatalysts with better light absorption capacity to mitigate energy issues. Herein, a new p-n heterojunction photocatalyst has been synthesized successfully using a polyoxometalate (POM), phosphomolybdic acid (PMo12), and zeolitic imidazolate framework (ZIF-9). Photoelectrochemical studies under visible-light irradiation revealed that ZIF-9–PMo12 exhibits a higher photocurrent density than pure ZIF-9. The support of ZIF-9 prevented the instability of PMo12 in aqueous solutions and improved the photoresponse ability of ZIF-9. The p-n junction formation impedes the recombination of electrons and holes, resulting in the improved photocatalytic property. Photoelectrochemical experiments confirmed the photocatalytic features, and thus this work paves the way for the development of an efficient, stable, and low-cost photocatalyst for green H2 generation.