Overcoming poisoning effects of heavy metal ions against photocatalysis for synergetic photo-hydrogen generation from wastewater

• Published in: Nano energy Vol. 38; pp. 494 - 503
• Main Authors: Xu, Yingfeng, Zhang, Chen, Lu, Ping, Zhang, Xiaohua, Zhang, Lingxia, Shi, Jianlin
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2017
• Subjects: Catalyst poisoning; Hybrid materials; Photocatalysis; Wastewater remediation; Catalyst poisoning; Wastewater remediation; Hybrid materials; Photocatalysis
• ISSN: 2211-2855
• DOI: 10.1016/j.nanoen.2017.06.019

The concept of photocatalytic H2 generation from wastewater provides potential simultaneous solutions for clean energy generation and wastewater remediation, which, however, suffers from the poisoning effect of wastewater-containing heavy metal ions against photocatalysis. Here, an innovative “trash-to-treasure” strategy is proposed to reuse the toxic heavy metal contaminants for enhanced H2 generation performance from wastewater via synergetic photocatalysis. Through fabricating a transparent adsorbent polysaccharides hydrogel to incorporate photocatalyst without deteriorating its photocatalytic activities, heavy metal ions could be efficiently collected on the well-designed system to minimize their influence on photocatalytic process. Then an in-situ sulfurization process was subsequently introduced to convert the adsorbed heavy metal ions into corresponding metal sulfide semiconductors with narrowed band-gap, concurrently forming heterojunction with incorporated photocatalysts, which resulted in the significantly elevated photocatalytic activities for H2 generation. Based on the detailed studies on both the performances and mechanism, this general and facial strategy firstly demonstrate the recycling of harmful heavy metal contaminants to overcome the adverse catalyst poisoning effect, and even to accomplish the elevated H2 photo-generation from wastewater, which may provide a promising yet practical solution for clean energy generation and wastewater purification. Wastewater-oriented “trash-to-treasure” strategy to convert heavy metal contaminants into efficient visible light photo-sensitizers, reversing the adverse catalyst poisoning effect and achieving an enhanced photocatalytic H2 productivity with synergetic wastewater remediation [Display omitted] •“Trash-to-treasure” strategy reverses photocatalyst poisoning effect in wastewater.•Combine photocatalyst and polysaccharides gel for efficient metal ion adsorption.•In-situ sulfurization converts heavy metal contaminants into photo-sensitizers.•Form heterojunction for improved photocatalytic H2 productivity with recycled uses.