We herein report that sulfur doping simultaneously endows Bi₂O₂CO₃ with promoted band energy structure and charge separation achieving high visible-light photocatalysis. Experimental and theoretical results showed that S doping brings about the downshift of the conduction band level and consequently a narrowed band gap. S-doped Bi₂O₂CO₃ unfolds drastically enhanced, visible-light active photocatalytic properties for MB decomposition and NO removal. The study may shed new light on design of new photocatalytic materials for solar-conversion applications.