In-situ construction of novel sulfur-vacancy-rich Bi/Bi2S3/SnS2 Z-scheme heterostructure photocatalysts for efficient Cr(VI) reduction and nitrogen fixation

Highly competent and economical photocatalysts are one of the most charming targets in environmental restoration and clean production. Herein, a novel sulfur-vacancy-rich Bi/Bi2S3/SnS2 Z-scheme heterostructure was constructed in situ and applied for the photoreduction Cr(VI) and nitrogen fixation. The fabricated Bi/Bi2S3/SnS2–2 exhibits the optimum photoreduction Cr(VI) performance with the efficiency of 94.5% within 15 min visible light irradiation. The remarkably enhanced catalytic efficiency derived from the synergistic effect of the construction of intimate contacted interface, abundant sulfur vacancy and surface plasmon resonance (SPR) effect of metal Bi. Meanwhile, the excellent photocatalytic nitrogen fixation property (96.4 μmol g–1 h–1) was achieved by Bi/Bi2S3/SnS2–2 under full solar illumination because sulfur vacancy could provide sufficient catalytic sites to accelerate the adsorption and nitrogen activation. The Z-scheme heterostructure was proposed to expound the photocatalytic mechanism. This work offers a new perspective on hierarchical heterostructure with plentiful vacancies for environmental remediation and energy development.