A Bi7.38Cr0.62O12+x crystal as a novel visible-light-active photocatalyst up to ∼650 nm

The relatively wide band gap (>2.0 eV) and limited light absorption ranges (only up to 600 nm) of photocatalysts severely restrict the exploitation of solar energy. Herein, we developed a Bi7.38Cr0.62O12+x crystal photocatalyst with a narrow band gap of 1.98 eV and a broad light absorption range of ∼650 nm. Unlike other broad light absorption range photocatalysts (up to ∼650 nm) such as red phosphorus, Fe2O3, and CdSe, which are either unstable or show low photocatalytic performances, the as-synthesized Bi7.38Cr0.62O12+x crystal photocatalyst exhibits a steady photocatalytic activity for the decomposition of methylene blue, methyl blue, and phenol, and production of O2.