M_(x)Co_(3)O_(4)/g-C_(3)N_(4) Derived from Bimetallic MOFs/g-C_(3)N_(4) Composites for Styrene Epoxidation by Synergistic Photothermal Catalysis

摘要

Although metal-organic frameworks(MOFs)have been widely reported as precursors for obtaining various porous materials in recent years,the limited MOF types and monofunctional active site of MOF-based catalysts remain to be hard to crack.Herein,bimetallic MOFs,MCo-ZIFs stabilized by graphitized carbon nitride(g-C_(3)N_(4))and their pyrolytic M_(x)Co_(3)O_(4)/g-C_(3)N_(4) hybrids(M=Zn,Cu,Fe,Ni)have been designedly synthesized.The obtained M_(x)Co_(3)O_(4)/g-C_(3)N_(4) hybrids display synergistic photothermal effect from both M_(x)Co_(3)O_(4) and g-C_(3)N_(4) under visible light irradiation.Significantly,the solution temperature can be heated from room temperature(20℃)to 66℃ after 40 min irradiation.Therefore,the catalytic activity of M_(x)Co_(3)O_(4)/g-C_(3)N_(4) exceeds those of most reported catalysts under mild reaction conditions.The optimal ZnxCo_(3)O_(4)/g-C_(3)N_(4) catalyst realizes 96%conversion and 75%selectivity toward styrene oxide within 20 min.Incredibly,the CuxCo_(3)O_(4)/g-C_(3)N_(4) could achieve up to 89%selectivity toward styrene oxide.To our knowledge,this is the first report about the novel photothermal effect of ZIFs-derived metal oxides.