Synergistic coupling of photocatalytic H2 evolution and selective oxidation of benzyl alcohol over ZnIn2S4/Ni in aqueous solution

Abstract

The synergistic coupling of photocatalytic hydrogen evolution and selective organic matter conversion is extremely attractive, as clean fuel and high value–added chemicals can be produced simultaneously with light as the sole energy input. Herein, we developed a dual functional photocatalyst (ZnIn₂S₄/Ni) for efficient photocatalytic conversion of benzyl alcohol into benzaldehyde with simultaneous hydrogen production. Consequently, ZnIn₂S₄/Ni displayed a top-level benzaldehyde and H₂ evolution rate even in aqueous media. The yield of benzaldehyde reaches 19.3 mmol/g/h, which is 33 times higher than that of naked ZnIn₂S₄ and even exceeds that of precious metal systems (Pt, Pd, Ru). Here, Ni site not only acted as an effective co–catalyst for charge separation, but also played an important role in accelerating the α–C–H bond cleavage during the dehydrogenation of benzyl alcohol. This work provides a cost-effective and green reference path for the efficient conversion of solar energy to chemical energy.