Photocatalytic CO2 reduction is a promising approach for reducing CO2 emissions and achieving the goal of carbon neutrality. In this work, selectively coupling Cu(OH)2 and CuO with amine-modified brookite TiO2 ( NH2–B–TiO2) has been achieved by a simple precipitation method. The results show that CuO is better than Cu(OH)2 as a co-catalyst to enhance the CO2 photoreduction capability of NH2– B–TiO2. The highest rates of CO2 conversion to CH4 and CO of NH2– B–TiO2–CuO composite reach 6.05 and 3.25 μmol h− 1 g− 1, respectively, which is higher than 8 times the yield of CH4 of NH2– B–TiO2. It is proposed that the NH2– B–TiO2–CuO composite offers an effective charge transfer through the formation of a p–n junction between NH2– B–TiO2 and CuO interfaces, while in the NH2– B–TiO2–Cu(OH)2 composite, the Cu(OH)2 dominantly serves as an electron sink to capture photo-induced electrons, promoting photo-induced carrier separation. This work provides an ingenious synthetic method for selectively anchoring Cu(OH)2 and CuO on semiconductors with different charge transfer routes for an efficient CO2 photoreduction.

Selectively anchoring Cu(OH)2 and CuO on amine-modified brookite TiO2 for enhanced CO2 photoreduction
    Abstract
        Graphical abstract
    1 Introduction
    2 Experimental
        2.1 Materials
        2.2 Sample preparation
        2.3 Samples’ characterization
        2.4 Photocatalytic performance measurement
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Zhangjing Chen(School of Chemistry and Environmental Engineering, Donghu New & High Technology Development Zone, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Liangliang Li(School of Chemistry and Environmental Engineering, Donghu New & High Technology Development Zone, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)
• Gang Cheng(School of Chemistry and Environmental Engineering, Donghu New & High Technology Development Zone, Wuhan Institute of Technology, Wuhan 430205, People’s Republic of China)