Enhancement of Sulfur Source-Dependent Zn Vacancies in Different Photocatalytic Performances of ZnIn2S4 Nanoparticles

This study focuses on the synthesis and investigationof ZnIn2S4 nanoparticle (NP) photocatalyststreated withdifferent sulfur sources, thioacetamide (TAA), or thiourea (TU), toexplore their wavelength-dependent photocatalytic activity. The researchaims to understand the impact of Zn vacancies present on the surfaceof ZnIn2S4 NPs. The investigation involves electronspin resonance and in situ X-ray photoelectron spectroscopy to studythe photocatalytic activity of ZnIn2S4-TUand ZnIn2S4-TAA NPs, following the characterizationof surface morphology and electronic properties using high-resolutiontransmission electron microscopy and X-ray diffraction. Additionally,the study delves into the wavelength-dependent photocatalytic degradation(PCD) activity of the ZnIn2S4 NPs using 2,5-hydroxymethylfurfural(HMF) across a wide range. Notably, the selective oxidation of HMFusing ZnIn2S4-TU NPs resulted in theformation of 2,5-furandicarboxylic acid (FDCA) via 2,5-diformylfuran,with an efficiency exceeding 40% over the broad wavelength range.The research demonstrates that the irradiation wavelength for PCDis influenced by the number of defect structures introduced into theZnIn(2)S(4) NPs through the sulfur source. By altering the sulfur source duringsynthesis, ZnIn2S4 NPs achieved efficient photocatalyticactivityby increasing Zn vacancies, enabling the selective oxidation of HMFto FDCA.