Microwave Synthesis of Cu/Cu₂O/SnO₂ Composite with Improved Photocatalytic Ability Using SnCl₄ as a Protector

Cu/Cu₂O/SnO₂ composites were successfully prepared with a facile microwave synthesis method. The structure of Cu/Cu₂O/SnO₂ composite was studied by morphology characterizations, such as X-ray diffraction, transmission electron microscopy and high-resolution transmission electron microscopy, which showed that the size of the Cu/Cu₂O/SnO₂ particles is 20–50 nm. The synthesis mechanism revealed that SnCl₄ obstructed between Cu(OH) and ethylene glycol, preventing Cu(OH) being reduced into Cu at high temperature. The photocatalytic property of Cu/Cu₂O/SnO₂ composite was investigated by degrading the mixed dyestuff under the irradiation of visible light at room temperature. Benefiting from the effect of electron transfer, the photocatalytic performance of the microwave-prepared Cu/Cu₂O/SnO₂ composite was much better than that of pure Cu₂O. The possible photocatalytic mechanism of the Cu/Cu₂O/SnO₂ composite catalysts was proposed and elaborated in this study. This synthesis of Cu/Cu₂O/SnO₂ composite may provide a method for other Cu₂O/semiconductor composites microwave preparation.