Local microenvironment regulation of MoS2−x/ZnIn2S4−x heterojunction for enhancing photocatalytic NO3− reduction

Constructing sulfur vacancies to increase the active edge sites of molybdenum disulfide (MoS2) is an effective strategy for enhancing the catalytic activity of cocatalysts in heterojunction materials. However, defects in the interface of traditional research can serve as carrier capture centers that significantly impede carrier migration. In this study, we propose an innovative carrier migration pathway to mitigate carrier recombination at interface vacancies by regulating the local microenvironment of MoS2−x/ZnIn2S4−x heterojunction (MOSZ). Fortunately, the optimized MOSZ3 exhibits outstanding NO3− reduction performance (185.59 µmol g−1 h−1) without the need for sacrificial agents. Density functional theory (DFT) calculations and experimental results collectively confirm that surface oxygen regulates the local microenvironment of heterojunctions, disrupting the localization effects of sulfur vacancies by inducing local charge polarization and creating a charge transport channel. This contributes to enhancing carrier migration and exciton dissociation. Furthermore, it also regulates the chemisorption and activation of NO3− as well as the energy required for deoxygenation and hydrogenation of intermediates. Our work not only provides a novel perspective on alleviating charge trapping in interfacial vacancies, but also offers new insights for environmental remediation and sustainable energy production.