MOF-derived carbon supporting tubular In2O3 for efficient photocatalytic degradation of antibiotics

Abstract

A series of graphite-carbon supporting tubular In2O3 (denoted as C-In2O3) were successfully synthesized by controlling calcination of In-MOF under air condition. In the annealing temperature of 400 ℃ under air condition, the crystallization of In3+ into In2O3 and conversion of organic ligands into graphite-carbon support for the translation of In-MOF into C-In2O3 was accomplished. Benefiting from the synthetic effects of tubular structure and the graphite-carbon support, C-In2O3 displayed a higher light absorption, light-to-electron efficiency, charge separation and interface transfer, which resulted in a remarkable photocatalytic activity of tetracycline (TC) degradation. Specially, the optimal C-In2O3-3 sample with a dosing of 30 mg exhibited a photocatalytic degradation efficiency of 97.1 % for TC in the concentration of 20 mg/L under visible light irradiation for 40 min. Photogenerated holes (h+) and •OH radicals from the activation of in-situ generated H2O2 were the main radical species in the photocatalytic degradation of TC. This work could offer new insights in controlling the thermal transformation pathway of MOF for synthesizing efficient photocatalysts for effective antibiotic removal.