Indium vacancy modulated BiVO4/ZnIn2S4 for photoelectrochemical production of ammonia

Background: Photoelectrochemical (PEC) reduction of nitrate to produce ammonia (NIRR) is a green strategy for converting waste NO3-into 3- into high-value chemicals. However, a lack of active sites and low selectivity still plague the single catalyst used to establish the PEC-NIRR system. Methods: Here, we construct a BiVO4/VIn-ZnIn2S4 4 /V In-ZnIn 2 S 4 (BVO/VIn-ZIS) I n-ZIS) heterostructure with indium vacancies. The introduction of indium vacancy significantly enhances the conversion of NO3-to 3- to NH3 3 by augmenting active sites and fostering carrier separation via the creation of a built-in electric field. Significant findings: NH3 3 yield of BVO/VIn-ZIS I n-ZIS heterostructure with moderate indium vacancy (BVO/VIn-ZIS-m) I n-ZIS-m) has been promoted to 15.26 mu g h- 1 cm- 2 (BVO/VIn-ZIS-m), I n-ZIS-m), and NH3 3 selectivity reaches 21.3 times that of NO2-. 2- . The results of cyclic experiments further demonstrate that NH3 3 yield of BVO/VIn-ZIS-m I n-ZIS-m has remained 98.4% after five cycles, due to its excellent durability. Therefore, this work demonstrates that indium vacancy could significantly modulate the PEC performance of BiVO4 4 to achieve an efficient NH3 3 production.