Metal-organic Framework-derived NiO/ZnO Composites for Photoelectrocatalytic Reduction of Cr(VI)

Abstract

Ni/Zn-MOF composites with photoelectrocatalytic (PEC) performance for Cr(VI) reduction were prepared via hydrothermal method and calcinating method. The as-prepared NiO/ZnO composites exhibited uniform morphology. When being subjected to an external voltage of 0.7 V and irradiated with visible light for 120 min, the NiO/ZnO composite exhibited a Cr (VI) reduction efficiency of almost 100 %, outperforming ZnO and NiO counterparts. The effects of the content of NiO to ZnO and different calcination temperatures on PEC performance were also investigated. Additionally, elimination experiments results indicated that photo-generated electrons (e⁻) play a crucial role in the catalytic reduction of Cr(VI). The notable enhancement in the photoelectrocatalytic performance can be credited to the applied bias voltage and the formation of a p-n heterojunction between NiO and ZnO. Consequently, the NiO/ZnO nanocomposites exhibit significant potential for the PEC reduction of Cr(VI). This capability underscores the promise of NiO/ZnO nanocomposites for applications in the photoelectrocatalytic reduction of Cr(VI) and related environmental remediation processes.