In2O3/Bi2Sn2O7 heterostructured nanoparticles with enhanced photocatalytic activity

Abstract In 2 O 3 /Bi 2 Sn 2 O 7 composite photocatalysts with various contents of cubic In 2 O 3 nanoparticles were fabricated by using impregnation method. A thriving modification of Bi 2 Sn 2 O 7 by an introduction of In 2 O 3 was confirmed by using X-ray diffraction, UV–vis diffuse reflectance spectrometry, transmission electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. The samples composed of hybrids of In 2 O 3 and Bi 2 Sn 2 O 7 exhibited a much higher photocatalytic activity for the degradation of Rhodamine B under visible light, as compared with pure In 2 O 3 and Bi 2 Sn 2 O 7 nanoparticles. Optimized composition of the composite photocatalysts was 0.1In 2 O 3 /Bi 2 Sn 2 O 7 , which shows a rate constant higher than those of pure In 2 O 3 and Bi 2 Sn 2 O 7 by 4.06 and 3.21 times, respectively. Based on Mott-Schottky analysis and active species detection, the photoexcited electrons in the conduction band of In 2 O 3 and the holes in the valence band of Bi 2 Sn 2 O 7 participated in reduction and oxidation reactions, respectively. Hence, OH, O 2 − and h + were the main active species involved in the photocatalytic reaction of the In 2 O 3 /Bi 2 Sn 2 O 7 composite photocatalysts. The effective separation process of the photogenerated electron-hole pairs was testified by photocurrent test.