Light-controlled convergence of photogenerated carriers and reactants to boost photocatalytic performance

Photocarriers and reactants are two crucial factors in photocatalytic reactions, the divergence between them severely limits the photocatalytic performance. Herein, we proposed a light-controlled method to converge photocarriers and reactants to the same location. Based on energy band engineering, we adjust the wavelength of the irradiated light to selectively grow cocatalyst in the desired position in a semiconductor. The pinpointed growth of the cocatalyst serves as a bridge between the photocarriers and the reactants, and thus improves the photocatalytic efficiency. We applied this strategy to the Ag/Cu2O photocatalyst, and the Ag was selectively grown on the edge, {1 1 1} facet and {1 0 0} facet of Cu2O, respectively. Benefiting from the synergy of the photocarriers and the reactants, the edge-preferred growth of Ag/Cu2O showed 30-fold increased degradation rate for MO and 6-fold increased photocurrent density for water splitting at 0 V vs. RHE compared with the bare Cu2O. This strategy has also been successfully applied to Pt/BiVO4, Ag/BiVO4 and MnOx/BiVO4 systems. This method opens up a new way for the rational design of high-performance photocatalysts.