BiVO₄ quantum dot-decorated BiPO₄ nanorods 0D/1D heterojunction for enhanced visible-light-driven photocatalysis

Herein, we report a BiVO4 quantum dot (QDs)-decorated BiPO4 nanorods 0D/1D heterojunction via an in situ growth method. It showed enhanced visible-light-driven photocatalytic activity for degrading Rhodamine B (Rh B) compared to its pristine counterparts in composite. The mass ratio of BiVO4/BiPO4 was then varied from 3 wt% to 50 wt% and the optimum value was found to be 30 wt%, showing 8.3-fold and 6.3-fold apparent reaction rates higher than those of pristine BiPO4 and BiVO4, respectively. Moreover, all of the reduced Rh B was transformed into CO2 and H2O during the photocatalysis, thus showing the good mineralization ability (almost 100%) of the composite. Furthermore, the photocatalytic mechanism of the composite was also investigated here by the zeta potential, scavenger experiments, electron paramagnetic resonance (EPR), photoluminescence spectroscopy (PL), transient photocurrent and electrochemical impedance spectroscopy (EIS). Results show that (i) ˙OH was the main reactive species and (ii) BiVO4 could form a heterojunction with BiPO4, thus widening the response range to the visible region and accelerating the charge separation and transfer.