Active sites modification and superior carriers separation synergistically boosted hydrogen production of Bi/Bi 2 MoO 6 /ZnIn 2 S 4 non-noble metal S-scheme photocatalyst.

Novel Bi/Bi ₂ MoO ₆ /ZnIn ₂ S ₄ is not only cost-effective compared to noble metals, but also shows superior hydrogen production. Comprehensive characterization illustrated that the S-scheme heterojunction and excellent photon utilization capability of the photocatalyst were the main factors that enhanced its hydrogen production performance. The X-ray photoelectron spectroscopy illustrated the elemental composition of the catalyst and the presence of Bi metal in ternary heterojunction. The photoluminescence and electrochemical characterization proved that S-scheme heterojunction Bi/Bi ₂ MoO ₆ /ZnIn ₂ S ₄ promoted the separation of photogenerated carriers. The amount of hydrogen produced by Bi/Bi ₂ MoO ₆ /ZnIn ₂ S ₄ was 2306.90 µmol g ^-1 under visible light illumination for 5 h. It was 4.3, 29.6 and 2.2 times more than those of ZnIn ₂ S ₄ , Bi ₂ MoO ₆ /ZnIn ₂ S ₄ and Pt/ZnIn ₂ S ₄ , respectively. The excellent hydrogen production activity of the ternary complexes may be attributed to the following: (1) Bi/Bi ₂ MoO ₆ could replace precious metals to enhance reactive sites of ZnIn ₂ S ₄ . (2) Metal Bi could produce surface plasmon resonance effect facilitating light absorption, and Bi acted as an electron bridge promoting charge transfer. (3) The charge transfer mechanism of S-scheme heterojunction and hot electrons injection process of Bi metal synergistically drove the photocatalytic hydrogen production. This work provides an innovative method for the construction of visible-light-driven photocatalysts without using precious metals.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier Inc. All rights reserved.)