Lattice expansion boosting photocatalytic degradation performance of CuCo2S4 with an inherent dipole moment

Realizing efficient charge separation and directional transfer is a challenge for single-component semi-conductors. The spatial electric field generated by dipole moment could promote charge separation. Here, three-dimensional hierarchical CuCo2S4 microspheres with lattice distortion were prepared, and lattice distortion was modulated by changing feed Co/Cu molar ratios in synthesis. CuCo2S4 showed asymmetric crystal structure, leading to generation of dipole moment. The charge separation efficiency of CuCo2S4 was related to lattice distortion, and lattice expansion was in favor for charge separation. The CuCo2S4 with feed Cu/Co molar ratio of 1:4 (CCS-4) showed the maximum lattice expansion and exhibited the highest photocatalytic activity, which was attributable to the highest charge separation efficiency and the largest specific surface area. CCS-4 can remove 95.4% of tetracycline hydrochloride within 40 min pho-tocatalysis, and effectively improve the biodegradability of pharmaceutical wastewater. Importantly, this study provides a new vision for constructing single-component photocatalysts with high photocatalytic performance.(c) 2022 Published by Elsevier B.V. on behalf of Chinese Chemical Society and Institute of Materia Medica, Chinese Academy of Medical Sciences.

Automated summary

Efficient charge separation and directional transfer are achieved in three-dimensional hierarchical CuCo2S4 microspheres with lattice distortion, which is modulated by changing Co/Cu molar ratios in synthesis. The asymmetric crystal structure of CuCo2S4 generates a dipole moment, promoting charge separation. The CuCo2S4 with a feed Cu/Co molar ratio of 1:4 shows the highest photocatalytic activity due to the highest charge separation efficiency and largest specific surface area. It can effectively remove 95.4% of tetracycline hydrochloride and improve the biodegradability of pharmaceutical wastewater.