Recent Trends on SPR Active Visible-Light Photocatalysts

An emerging research topic is the harvesting of abundant and renewable sunlight in energy production and environmental remediation. Indeed, research on solar-driven heterogeneous photocatalysis through surface plasmon resonance (SPR) has seen rapid growth and potentially opens a technologically promising avenue that can benefit the sustainable development of global energy and the environment. The strong interaction between light and plasmonic nanostructures provides the energy transduction is needed for the photocatalytic conversion.

Figure 1. Schematic diagram of hydrogen production from Ag/AgBr/g-C₃N₄[1].

Y. Che et al., have recently found that the significant factors for enhancing properties were due to the synergistic effect between Ag/AgBr and g-C₃N₄, and the enhancement of light absorption by the SPR effect of Ag nanoparticles (NPs) [1]. Ag/AgBr NPs were firmly anchored on the surface of g-C₃N₄ and their high dispersion was also responsible for the improved activity, long-term recycling ability and deals with possible reaction mechanism (Figure 1). The researchers have also summarized some important previous works related with Ag/AgCl which exhibits excellent visible light absorption performance due to the synergistic effect of Ag/AgCl and SPR effect of Ag NPs, Ag@AgCl, Ag/AgCl/TiO₂nanotube arrays and Ag/AgCl/Al₂O₃ and which showed high visible light photocatalytic activity performance in degradation of organic pollutants, organic synthesis and water splitting. The researchers have developed a ternary visible-light-response plasmonic photocatalyst Ag/AgBr/g-C₃N₄ using green and handy route. These reports have highlighted that a ternary visible-light-response plasmonic photocatalyst has exhibited a high visible-light photocatalytic activity for water splitting to generation hydrogen without Pt co-catalyst.

Generally, Au, Ag, Cu and Al metallic nanoparticles are used as plasmonically active photocatalysts for a wide range of chemical reactions, such as CO₂ conversion into useful chemicals and fuels [2] and some important selective oxidation reactions [3].

More recently, complexes that combine plasmonically active metal ‘antenna’ nanoparticles with catalytically active ‘reactor’ materials have been found to improve further photocatalytic efficiency, selectivity and specificity [4]. In this configuration, the local optical field induced by the antenna can effectively convert the catalyst into a photocatalyst.

L. Zhou et al., from Princeton University, Princeton, USA have reported Cu-Ru single-atom alloy nanoparticles as highly efficient and coke-resistant plasmonic photocatalysts for methane dry reforming (MDR) [5].

Figure 2.The visible light photocatalytic reaction mechanism of AgCl loaded Sn-TiO₂ catalyst [6].

Our recent publications were related to the SPR system supported metal oxide coupled semiconductor which canact as an efficient visible light photocatalyst, and the work was performed at Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China on collaboration with Prof. J. Wang, MEDC. We have highlighted that the AgCl NPs were loaded on tin doped with a titania microsphere in tune with visible-light activity [6]. For the complete understanding, the photocatalytic property of the AgCl loaded Sn-TiO₂ NPs microspheres, and the possible mechanism of photocatalytic degradation of organic pollutants on the hybrid was proposed in Figure 2.

The SPR-mediated photocatalysis not only impacts the basic science of heterogeneous photocatalysis, but generate new concepts guiding with practical technologies such as wastewater treatment, air purification, selective oxidation reactions, selective reduction reactions and solar-to-hydrogen energy conversion in an energy efficient and environmentally benign approach. From these reports, we have concluded that the SPR photocatalysts are the best visible-light photocatalysts for energy and environmental applications. For the commercial applications, still it needs further development.

References

Y. Che et al., Scientific Reports 10, 721 (2020).
W. B.Hou, et al. ACS Catal.1, 929 (2011).
A. Marimuthu, et al., Science 339, 1590 (2013).
U. Aslamet al.,Nat. Nanotechnol. 12,1000 (2017).
L. Zhou et al., Nat. Energy, 5, 61 (2020).
A.S. Ganeshrajaet al., Appl. Surf. Sci. 441,678 (2018).

Blog Written By

Dr. A. S. GANESHRAJA

National College, Thiruchirappalli

Tamilnadu, India

Editors

Dr. S. Chandrasekar

Dr. K. Rajkumar

Reviewers

Dr. Y. Sasikumar

Dr. S. Thirumurugan

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