A novel carbon quantum dots (CQDs) modified Cs_4PW_(11)O_(39)Fe(Ⅲ)(H_2O) material to achieve high photocatalytic property

摘要

Keggin-type polyoxometalates is a kind of promising photocatalyst with adjustable light absorption range. However, the high recombination rate of photogenerated charge carriers hampered its photocatalytic efficiency. To solve this weakness, novel carbon quantum dots (CQDs) modified Cs4PW(11)O(39)Fe(III)(H2O) photocatalysts (CQDs/Cs4PW11Fe) have been synthesized via a hydrothermal process. Phase structure, morphology, optical and electronic properties of the as prepared photocatalysts were systematically characterized by XRD, SEM, TEM, DRS and surface photovoltage tests. It could be found that CQDs was well deposited on the surface of Cs4PW11Fe, which has broadened the light absorption of Cs4PW11Fe. The photodegradation efficiencies of the CQDs/Cs4PW11Fe composite photocatalysts for RhB under visible light irradiation were clearly enhanced. Trapping experiments were carried out to detect the photocatalytic mechanisms. The charge transfer and separation efficiencies of the samples were confirmed by electrochemical impedance spectroscopy tests.