Herein, a novel Bi(OH)3 photocatalyst was successfully synthesized. Benefiting from the suitable band positions, abundant alkaline groups and oxygen vacancies, the as-prepared semiconductor exhibits efficient activity in both photocatalytic CO2 reduction with a CO production rate of 36 μmol g-1 h-1 and phenol decomposition with a 92.7% degradation rate in 180 min.