Construction of a Visible-Light-Response Photocatalysis-Self-Fenton Degradation System of Coupling Industrial Waste Red Mud to Resorcinol-Formaldehyde Resin.

Heterogeneous photocatalysis-self-Fenton technology is a sustainable strategy for treating organic pollutants in actual water bodies with high-fluent degradation and high mineralization capacity, overcoming the limitations of the safety risks caused by adding external iron sources and hazardous chemicals in the homogeneous Fenton reaction and injecting high-intensity energy fields in photo-Fenton reaction. Herein, a photo-self-Fenton system based on resorcinol-formaldehyde (RF) resin and red mud (RM) was established to generate hydrogen peroxide (H2O2) in situ and transform into hydroxy radical (•OH) for efficient degradation of tetracycline (TC) under visible light irradiation. The capturing experiments and electron spin resonance (ESR) confirmed that the hinge for the enhanced performance of this system is the superior H2O2 yield (499 µM) through the oxygen reduction process (ORR) of the two-step single-electron over the resin and the high concentration of •OH due to activation effect of RM. In addition, the Fe2+/Fe3+ cycles are accelerated by photoelectrons to effectively initiate the photo-self-Fenton reaction. Finally, the possible degradation pathways were proposed via liquid chromatography-mass spectrometry (LC-MS). This study provides a new idea for environmental recovery in a waste-based heterogeneous photocatalytic self-Fenton system.

Plasmonic coupling-boosted photothermal composite photocatalyst for achieving near-infrared photocatalytic hydrogen production.

The development of photocatalysts that effectively utilize low-energy photons for efficient photocatalysis still faces a number of challenges. Herein, an efficient NIR-driven system based on WO3-x/ZnIn2S4 (WO3-x/ZIS) prepared by a simple low-temperature water-bath method, and the optimal WO3-x/ZIS-3 composites can reach a hydrogen-production efficiency of 14.05 µmol g-1h-1 under NIR light irradiation. The localized surface plasmon (LSPR) resonance effect in WO3-x quantum dots (QDs) not only broadens the ZIS photo-response range, but also the photothermal effect of WO3-x can increase the local reaction temperature of WO3-x/ZIS composite system, thus enhancing the photothermal-assisted photocatalytic activity. In addition, density functional theory (DFT) calculations show that the difference in work function between WO3-x and ZIS can lead to the formation of interfacial electric field (IEF), which not only promotes the separation and migration efficiency of photogenerated carriers, but also facilitates the photocatalytic water splitting for hydrogen production. This study provides possible directions for the construction of NIR-driven photothermal-assisted photocatalytic hydrogen production system.