Synthesis of 2D/2D CoAl-LDHs/Ti3C2Tx Schottky-junction with enhanced interfacial charge transfer and visible-light photocatalytic performance

Abstract The layered double hydroxides (LDHs) are potential non-noble metal photocatalysts. Unfortunately, the intrinsic activity of bulk LDHs is relatively low, which limits their use. Herein, the ultrathin, porous and vacancy-rich CoAl-LDHs nanosheets were prepared by exfoliation strategy. Then, they were assembled with the early transition-metal carbides nanosheets (MXenes, Ti3C2Tx) to afford a hybrid 2D/2D CoAl-LDHs/Ti3C2Tx photocatalyst via electrostatic assembly process. The experiments indicated that the CoAl-LDHs/Ti3C2Tx hybrids performed an excellent visible-light photocatalytic activity for tetracycline hydrochloride (96.67 %) degradation. Diversified characterization techniques (SEM, TEM, AFM, N2 adsorption-desorption analysis, XRD, FTIR, UV–vis DRS, photoelectrochemical test) and density functional theory calculations (electronic and optical properties) have indicated that such excellent photocatalytic activity was ascribed to the synergy and the Schottky heterojunction formation between CoAl-LDHs nanosheets and Ti3C2Tx nanosheets, which possessed markedly visible-light absorption, high specific surface area, rapid electrons transfer and depressed electron-hole pairs recombination.