Enhancing the activity and stability of Cu 2 O nanorods via coupling with a NaNbO 3 /SnS 2 heterostructure for photoelectrochemical water-splitting

• Published in: New journal of chemistry 2023-03, Vol.47 (13), p.6294-6304
• Main Authors: Tiwari, Shalini, Yadav, Priyanka, Ganguli, Ashok K.
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/D3NJ00684K

Fabrication of a NaNbO 3 /SnS 2 /Cu 2 O heterostructure was undertaken for the application of photoelectrochemical water-splitting. A type-II band alignment for charge carrier migration ( i.e. , electrons and holes) provided a high rate of charge transfer at the interface of the heterostructure, which aided prevention of photocorrosion and broadened the absorption range from the ultraviolet region to the visible region. Type-II band alignment was created in a NaNbO 3 /SnS 2 heterojunction. Another type-II band alignment was formed in SnS 2 /Cu 2 O with a n–p-type heterojunction. Linear sweep voltammetry (LSV) plots of the NaNbO 3 /SnS 2 /Cu 2 O heterostructure showed higher photocurrent density at a low onset potential. Mott–Schottky plots confirmed formation of a n–n–p heterojunction in the composition of NaNbO 3 /SnS 2 /Cu 2 O, which helps to lower the recombination rate of charge carriers. Electrochemical impedance spectroscopy (EIS) suggested a smaller value of charge transfer resistance of the NaNbO 3 /SnS 2 /Cu 2 O heterostructure; these data supported the evidence that migration of charge carriers was much more favorable in the designed heterostructure, which exhibited higher activity towards photoelectrochemical water-splitting.