One-step solvothermal fabrication of Cu@PANI core–shell nanospheres for hydrogen evolution

Polyaniline(PANI)-decorated Cu nanoparticles were prepared by a facile solvothermal method. Different reaction temperatures resulted in different morphologies of the Cu/PANI composites, which exhibited good photocatalytic activities. When the mass ratio of PANI increased to 2.5 wt%, the H2 evolution rate reached 1.97 mmol g−1 h−1 in lactic acid solution under solar light irradiation, which is about 2 times higher than that of pure Cu nanoparticles (1.06 mmol g−1 h−1). The introduction of PANI can improve the separation efficiency of the photo-generated electron–hole pairs, where PANI acts as a hole reservoir for trapping holes generated by the Cu NPs and hindering the recombination of the electron–hole pairs. A possible mechanism is presented to explain the photocatalytic process using Cu@PANI core–shell nanospheres as the photocatalyst.