Atomically dispersed transition metal ion doped CdZnS nanocrystals were synthesized to delicately tune the selectivity for CO2 photoreduction to CH4, among which the CZS–Cu2+ achieved an excellent CO2-to-CH4 conversion rate of ca. 665.9 μL h−1 g−1 with a high selectivity of ca. 79.7% under visible irradiation.
