Microsphere structure enhances the photocatalytic performance of TiO2-CdS heterojunction

Abstract

Herein, a novel TiO2 microsphere structure (TMS) was reported for the first time, formed through the self-assembly of TiO2 nanocone monomers. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis revealed that the microsphere structure substantially boosted the growth density of TiO2 nanocone monomers, facilitating CdS loading. Photocurrent characterization revealed that CdS/TMS heterojunction (CTMS) exhibited a heightened photocurrent response than that of our previously reported CdS/TiO2 nanocone arrays (CTNC), suggesting that the microsphere structure enhanced photon absorption and electron-hole pair transmission channels for TiO2-CdS heterojunctions per unit area. Photocatalytic degradation experiments of tetracycline (TC) demonstrated that CTMS exhibited superior performance, achieving the degradation of 84.9 % of TC within 45 min, high than that of our previously reported CTNC (69.9 %). First-order kinetic fitting indicated that the degradation kinetic constant of CTMS (0.042 min−1) was 1.45 times higher than that of our previously reported CTNC (0.029 min−1).