Enhanced photocatalytic removal of nitric oxide over Ag-decorated ZnSn(OH)6 microcubes

Abstract

Presently, most of the population has been facing a string of severe climate change problems that primarily come from the intensive emission of nitric oxide (NO), which requires a practical approach to sustain our living conditions. Herein, Ag nanoparticles-decorated ZnSn(OH)6 microcubes (Ag:cZHS) photocatalysts were synthesized rapidly and used for photocatalytic NO removal under solar light activation. The properties of the newly prepared photocatalysts are comprehensively characterized by a series of routine methods. The NO removal performance over the ZnSn(OH)6 microcubes (c:ZHS) photocatalysts was increased markedly upon being combined with Ag nanoparticles through the surface plasmon resonance effect. The contribution of e−, h+, •OH, and •O2 was extensively investigated through trapping tests and electron spin resonance analysis (ESR). Also, the by-products and apparent quantum efficiency of the cZHS photocatalysts were studied.

Photoredox-Catalyzed Decomposition of Nitric Oxide over Au-Enhanced Surface Plasmon Resonance ZnSn(OH)6 Microcubes

“…On the other hand, for the effect of the single metal to support the photoredox-catalytic NO degradation, our previous study showed a high removal efficiency from the support of Ag NPs. In comparing the previous research and this study, the Au NPs offer higher stability and lower toxical production (Pham et al, 2022). However, the NO removal efficiency of the Au:cZHS was lower than Ag:cZHS.…”

“…6(a), the samples strongly absorb photons with a wavelength in the range of UV and visible light (λ > 200 nm). In addition, the peaks in the range of UV light (λ ~340 nm) and visible light (λ ~550 nm) of Au:cZHS can indicate the presence of Au NPs with the surface plasmon resonance (Fu et al, 2021a;Pham et al, 2022). The bandgap of samples was calculated by the Kubelka -Munk plots (Fig.…”

“…Based on the ESR results, the •OH radicals contributed the most to the photoredox-catalytic reactions. Ângelo et al, 2013;Pham et al, 2022;Van Pham et al, 2022). The photoredox-catalytic NO conversion pathway (Fig.…”

“…The flow rate of the experiment was 1.5 L min -1 , and the humidity was around 50%. Based on the photocatalytic system design (Pham et al, 2021a(Pham et al, , 2022, the humidity is strongly connecting to via control of the flow rate, which means that the humidity of 50% at the flow rate 1.5 L min -1 . The 100 ppm of NO gas (N2 balanced, Ming Yang Co) was diluted with zero air ( Model 1001, Sabio Instruments) until it reached 500 ppb.…”

“…Recent studies show remarkable achievements in applying the SPR of noble metals to enhance the light absorption of cZHS. For example, the photocatalyst efficiency of ZHS was significantly increased with the help of silver nanoparticles (Ag NPS) (Pham et al, 2022), golden nanoparticles (Au NPs) (Wu and Chen, 2015), bismuth nanoparticles (Bi NPs) (Wang et al, 2017), Ag@Ag3PO4 (Chen et al, 2016), etc. In particular, Au NPs have been reported that it can enhance photoelectricity, photo electricity, and charge separation of the substrate materials (Subramanian et al, 2004;Gupta and van Huis, 2019).…”