Insight into the Catalytic Behavior in Nitroarenes Reduction over Non-Noble Metals Modified Polymer Carbon Nitride

摘要

Revealing the catalytic mechanism and dynamic process in heterogeneous catalysis is fundamental and tremendous important.Here,non-noble metals(Bi,Cu,Cu2O or CuO)hybrided polymer carbon nitride nanosheets(CNN)were fabricated through ions intercalation processes.The prepared Bi-CNN hybrid exhibits moderate catalytic activity compared with Cu–CNN in 4-nitrophenol(4-NP)reduction.The kinetic rate constant and apparent active energy of Bi-CNN are 0.04 min~(-1)(20 °C)and 53.6±4.8 kJmol~(-1),respectively.Cumodified CNN shows a rate of 0.65 min~(-1),which is 16 times higher than that of Bi-CNN and even higher than noble metal(Au,Ag)-CNN hybrids.More importantly,a new catalytic behavior that no delay time(usually reported by using noble metals and metal oxides)was observed in the 4-NP reduction over Bi-CNN and Cu–CNN hybrids.A possible catalytic mechanism elaborated this new catalytic phenomenon was proposed based on the chemical redox potentials.The CuO-CNN and Cu2O-CNN hybrids were further prepared to verify the proposed catalytic model.This work provides more insight into the mechanistic investigation of nitroarenes reduction over non-noble metal catalyst evolved photocatalytic systems.