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Plasmonic Switching of the Reaction Pathway: Visible‐Light Irradiation Varies the Reactant Concentration at the Solid–Solution Interface of a Gold–Cobalt Catalyst
摘要： Product selectivity of alkyne hydroamination over catalytic Au2Co alloy nanoparticles (NPs) can be made switchable by a light-on/light-off process, yielding imine (cross-coupling product of aniline and alkyne) under visible-light irradiation, but 1,4-diphenylbutadiyne in the dark. The low-flux light irradiation concentrates aniline on the catalyst, accelerating the catalytic cross-coupling by several orders of magnitude even at a very low overall aniline concentrations (1.0 X 10@3 mol L@1). A tentative mechanism is that Au2Co NPs absorb light, generating an intense fringing electromagnetic field and hot electrons. The sharp field-gradient (plasmonic optical force) can selectively enhance adsorption of light-polarizable aniline molecules on the catalyst. The light irradiation thereby alters the aniline/alkyne ratio at the NPs surface, switching product selectivity. This represents a new paradigm to modify a catalysis process by light.
关键词： product selectivity,reaction pathway,selective adsorption,visible-light photocatalysis,plasmonic metal nanoparticles
更新于2025-09-19 17:13:59
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Highly Efficient and Robust Photocatalytic Systems for CO <sub/>2</sub> Reduction Consisting of a Cu(I) Photosensitizer and Mn(I) Catalysts
摘要： The development of highly efficient, selective, and durable photocatalytic CO2 reduction systems that only use earth-abundant elements is key for both solving global warming and tackling the shortage of energy and carbon resources. Here, we successfully developed CO2 reduction photocatalysts using [Cu2(P2bph)2]2+ (CuPS) (P2bph = 4,7-diphenyl-2,9-di(diphenylphosphinotetramethylene)-1,10-phenanthroline) as a redox photosensitizer and fac-Mn(X2bpy)(CO)3Br (Mn(4X)) (X2bpy = 4,4′-X2-2,2′-bipyridine (X = ?H and ?OMe) or Mn(6mes) (6mes = 6,6′-(mesityl)2-2,2′-bipyridne)) as the catalyst. The most efficient photocatalysis was achieved by Mn(4OMe): The total quantum yield of CO2 reduction products was 57%, the turnover number based on the Mn catalyst was over 1300, and the selectivity of CO2 reduction was 95%. Electronic and steric effects of the substituents (X) in the Mn complexes largely affected both the photocatalytic efficiency and the product selectivity. For example, the highest selectivity of CO formation was achieved by using Mn(6mes) (selectivity SCO = 96.6%), whereas the photocatalytic system using Mn(4H) yielded HCOOH as the main product (SHCOOH = 74.6%) with CO and H2 as minor products (SCO = 23.7%, SH2 = 1.7%). In these photocatalytic reactions, CuPS played its role as an efficient and very durable redox photosensitizer, while remaining stable in the reaction solution even after a turnover number of 200 had been reached (the catalyst used had a turnover number of over 1000).
关键词： turnover number,Cu(I) photosensitizer,Mn(I) catalysts,photocatalytic CO2 reduction,earth-abundant elements,quantum yield,product selectivity
更新于2025-09-09 09:28:46
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Development of Graphene Based Photocatalysts for CO2 Reduction to C1 Chemicals: A brief Overview
摘要： Transformation of CO2, a notorious greenhouse gas, to solar fuels is a promising strategy to alleviate the issues of global warming, environmental pollution, and climatic changes. Additionally, the CO2 conversion to useful chemicals/ fuels also possess a great potential to well match the energy demand in a sustainable manner. Hence, such exceptional benefits of harnessing CO2, by capitalizing sunlight, to valuable chemicals/fuels through photocatalysis, as one of the effective approach in the respective domain, have triggered great interest among researchers and scientific community. In this regard, utilization of customary and standard photocatalytic materials, specifically metal oxides like TiO2, are modified to provide enhanced performance, which is usually restricted due to limited intrinsic optical and physicochemical properties. To overcome such a critical issue of limited performance, several strategies like metals and non-metals doping, hetero-junctions, composites and nanostructures formation of photocatalytic materials have been investigated. Recently, with the invention of graphene and its derivatives, graphene based photocatalytic materials have been a topic of great interest, specifically for photocatalysts development and photocatalysis application. Graphene and its derivatives, due to their extraordinary physiochemical and electrical properties like high surface area, stability, anticorrosion capacity, photosensitizer, and excellent conductivity, can knock out the performance limiting constraints faced by traditional photocatalysts. Thus, Graphene based photocatalysts can be a feasible strategy to break new grounds in the field of photocatalytic CO2 reduction (PCCR) to useful chemicals/ fuels, i.e. conversion of sunlight to fuels. Herein, a summarized overview is presented for the latest development in graphene-based photocatalysts, focusing various strategies and researches being investigated in relation to the, utility of graphene and its derivatives for solar fuels generation, particularly C1 chemicals like CO, CH4, CH3OH, and insights to their role in improving efficacy of photocatalysts.
关键词： Photocatalytic activity,Photocatalytic CO2 reduction,Solar fuels,Product Selectivity,Graphene based photocatalysts
更新于2025-09-09 09:28:46