Pristine narrow-bandgap Sb2S3 as a high-efficiency visible-light responsive photocatalyst

Pristine Sb2S3, prepared by solid state reaction, was found to have an optical absorption edge of about 800 nm and a band gap of about 1.55 eV. Its photocatalytic activity was investigated by degrading methyl orange directly in the deionized water solution under visible light. Sb2S3 performed much better than P25, Bi2S3 and CdS under the same condition. The high-efficiency of Sb2S3 is due to the broad spectrum response and the suitable valence band position.