Towards full-spectrum photocatalysis: Achieving a Z-scheme between Ag2S and TiO2 by engineering energy band alignment with interfacial Ag
photocatalysis, Z-scheme, semiconductor, band structure, water splitting
A Z-scheme is a promising approach to achieve broad-spectrum photocatalysis. Integration of TiO2 with another semiconductor with a band gap of ~1.0 eV would be ideal to harvest both ultraviolet and visible-near infrared light for photocatalysis; however, most narrow-bandgap semiconductors have straddling band structure alignments with TiO2, constituting an obstacle to forming the Z-scheme for photocatalytic hydrogen production. In this communication, we demonstrate Ag2S as a model system where the energy band upshift of the narrow-bandgap semiconductor that shares an interface with a metal can overcome this limitation. To fabricate the design, we developed a unique approach to synthesize Ag2S–Ag–TiO2 hybrid structures. The obtained ternary hybrid structures exhibited dramatically enhanced performance in photocatalytic hydrogen production under full-spectrum light illumination. The activities were significantly higher than the sum of those of Ag2S–Ag–TiO2 structures under λ 400 nm irradiation as well as those of their counterparts under any light illumination conditions.
Tsinghua University Press
Yanrui Li,Leilei Li,Yunqi Gong,Song Bai,Huanxin Ju,Chengming Wang,Qian Xu,Junfa Zhu,Jun Jiang,Yujie Xiong, Towards full-spectrum photocatalysis: Achieving a Z-scheme between Ag2S and TiO2 by engineering energy band alignment with interfacial Ag. NanoRes.2015, 8(11): 3621–3629