Construction of CDs/CdS photocatalysts for stable and efficient hydrogen production in water and seawater

• Published in: Applied catalysis. B, Environmental Vol. 242; pp. 178 - 185
• Main Authors: Zhu, Cheng, Liu, Chang’an, Fu, Yijun, Gao, Jin, Huang, Hui, Liu, Yang, Kang, Zhenhui
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2019; Elsevier BV
• Subjects: Cadmium; Cadmium sulfide; Carbon dots/cadmium sulfide hybrid; Charge efficiency; Chemical analysis; Chemical reactions; Composite materials; Electronics industry; High efficiency and stability; Hydrogen; Hydrogen production; Improved charge transport and separation; Irradiation; Light irradiation; Photocatalysis; Photocatalysts; Photocatalytic hydrogen production; Radiation; Seawater; Water analysis; Water and seawater; Carbon dots/cadmium sulfide hybrid; Improved charge transport and separation; High efficiency and stability; Photocatalytic hydrogen production; Water and seawater
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2018.09.096

Through coordination between cocatalyst and morphology, the optimal CDs/CdS composite exhibits the highest hydrogen production rate of 4.64 mmol h−1 g−1 (6.70 mmol h−1 g−1) and AQE of 11.80% (19.30%) under the light wavelength of 420 nm in seawater (water), which are about 265 and 169 (78 and 77) times of those of the non-modified irregular CdS in the same condition. [Display omitted] •A series of CDs/CdS with four morphologies were synthesized.•The photocatalytic activity of samples is evaluated in both water and seawater.•The optimal CDs/CdS nanosheet exhibits prominent H2 production in both water and seawater.•The boost of the photocatalytic activity and stability is ascribed to the role of CDs. Photocatalytic hydrogen production on semiconductors has been intensively researched in the past years, yet it still lacks research on efficient and stable photocatalysis in seawater. In this paper, with cadmium sulfide (CdS) as a sample photocatalyst and carbon dots (CDs) as cocatalyst, we fabricated a series of CDs/CdS composites serving as efficient hydrogen production photocatalysts in both water and seawater. In this case, the optimal CDs/CdS-S composites (nanosheet with cocatalyst content of 0.01 gCDs/gcatalyst) exhibit prominent H2 production rate of 4.64 mmol h−1 g−1 (6.70 mmol h−1 g−1, water) and AQE of 11.8% (19.3%, water) under 420 nm light irradiation in seawater, which are about 265 and 169 (78 and 77, water) times of those of the non-modified irregular CdS in seawater, respectively. The excellent activity and stability are attributed to the competency of CDs that not only dramatically improves the charge separation efficiency, but also plays indispensable role in resisting the distraction from various ionic components in seawater. We hope our work can provide a feasible perspective for constructing high-efficient photocatalyst towards practical applications.