Photoelectrochemical hydrogen generation at hybrid rGO-Sn3O4/SnO2 nanocomposite

This study investigates the photoelectrocatalytic water splitting at Sn 3 O 4 and ternary rGO-Sn 3 O 4 /SnO 2 heterostructure nanocomposite materials. The nanocomposite exhibited superior performance compared to Sn 3 O 4 , a result which was related to stronger absorption in the visible region, narrower band gap energy (1.8 eV), and higher photocurrent under both UV/Vis and visible light irradiation. The nanocomposite was also more efficient at photoexcited charge separation, as reflected in the enhanced H 2 evolution. H 2 production at the rGO-Sn 3 O 4 /SnO 2 electrode reached a value that was twice as high as that of Sn 3 O 4 under optimized photoelectrochemical conditions and UV/Vis irradiation. UV–Vis light induced a faster charge carrier on the nanocomposite’s surface due to the direct excitation of SnO 2 and to posterior electron transfer to the reduced graphene oxide (rGO) followed by electron recombination at Sn 3 O 4 , as well as to electron excitation to the conduction band of Sn 3 O 4 and further H 2 evolution. This work provides an easy and low-cost method for obtaining Sn 3 O 4 -based materials for the production of clean energy. Graphical abstract