Efficient Photocatalytic Conversion H ₂ S to H ₂ and Na ₂ S ₂ O ₃ Over Ni ₃ S ₄ /Cd _0.5 Zn _0.5 S Schottky Junction in NaOH/Na ₂ SO <sub>3</s

ABSTRACT The photo‐driven conversion of toxic hydrogen sulfide (H 2 S) waste gas into hydrogen (H 2 ) and high‐value sulfur‐containing chemicals is of great significance to the coal chemical and petrochemical industries. In this paper, Ni 3 S 4 with excellent electrical conductivity was loaded on the surface of Cd 0.5 Zn 0.5 S (CZS) solid solution to construct a Ni 3 S 4 /CZS interfacial Schottky junction photocatalyst. The research shows that Ni 3 S 4 significantly improves the charge separation efficiency on the substrate surface. Using the saturated solution obtained by absorbing H 2 S with 0.2 mol L −1 (M) NaOH and 0.6 M Na 2 SO 3 as the reaction solution, the H 2 production rate of the 2 wt.% Ni 3 S 4 /CZS composite can reach 171.3 mmol g −1 h −1 . Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy confirmed that the sulfur compounds in the reaction solution were almost completely converted into Na 2 S 2 O 3 . The above Schottky junction composite provides an important experimental reference for the development of an efficient H 2 S photocatalytic conversion system and the simultaneous production of H 2 and Na 2 S 2 O 3 .