Highly dispersed and low-metal-loading CuOx@BiVO4 for efficient visible-light-driven photocatalysis

[Display omitted] •Highly dispersed low-metal loading CuOx@BiVO4 nanocomposites were fabricated.•CuOx@BiVO4 exhibited high visible-light-driven TC-HCl photocatalytic degradation and stability.•The main active species of CuOx@BiVO4 are h+, ·OH and ·O2–.•The loading of CuOx facilitates the formation of ·O2– and ·OH in CuOx@BiVO4. In this work, highly dispersed and low-metal loading CuOx@BiVO4 nanocomposites were fabricated via a multistep method. The fabricated samples exhibited excellent stability and a dependent tetracycline hydrochloride photocatalysis degradation efficiency on CuOx loading ratio, among which 0.4 %CuOx loading sample displayed best photocatalytic performance under visible light illumination. The loading CuOx significantly broadened the spectrum absorption range, enhanced the photogenerated electron-hole pairs separation and facilitated the formation of ·O2– and ·OH in CuOx@BiVO4. Moreover, the trapping experiments proved the crucial roles of h+, ·OH and ·O2– in the photodegradation process. Finally, a plausible photocatalytic mechanism has been proposed based on all analytical results.