Syntheses of Hexagonal and Cubic ZnIn2S4 Nanosheets for the Photocatalytic Reduction of CO2 with Methanol

ZnIn₂S₄ nanosheets with hexagonal and cubic structures, have been prepared through a liquid ultrasonic exfoliation method and another strategy involving a lamellar hybrid, respectively. The structure, morphology, and composition properties of the as-prepared samples were characterized using X-ray powder diffraction, UV−vis spectrophotometer, transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The as-prepared ZnIn₂S₄ nanosheets both displayed high photocatalytic conversion efficiency of CO₂ into methyl formate using methanol as solution of absorbing CO₂ and reducing agent. Interestingly, the hexagonal ZnIn₂S₄ showed higher activity and better stability than cubic ZnIn₂S₄.