Morphology-controlled synthesis of sunlight-driven plasmonic photocatalysts Ag@AgX (X = Cl, Br) with graphene oxide template

Abstract

5Novel cubic Ag@AgX@Graphene (X=Cl, Br) nanocomposites are facilely manipulated by means of a graphene oxide (GO) sheets-assisted assembly protocol, where GO sheets act as amphiphilic template for hetero-growth of AgX nanoparticles. A morphology transformation of AgX nanoparticles from sphere to cube-like was accomplished by involving GO. With a further UV irradiation, the reduction of GO to graphene and the generation of Ag nanocrystals on AgX occur simultaneously. We have demonstrated 10 that thus-produced Ag@AgX@Graphene nanocomposites could be employed as stable plasmonic photocatalysts to decompose acridine orange as a typical dye pollutant under sunlight irradiation. Compared with the bare quasi-spherical Ag@AgX, such graphene-interfaced cubic Ag@AgX nanocomposites display distinctly higher adsorptive capacity, smaller crystal size and reinforced electronhole pair separation owing to the interfacial contact between Ag@AgX and graphene sheets components, 15 resulting in an enhanced photocatalytic decomposition performance. This investigation provides new possibilities for the development of morphology-controlled plasmonic photocatalysts and facilitates their practical application in environmental issues.

Graphene in Photocatalysis: A Review

“…In another example, to fabricate Ag–RGO–Bi 2 WO 6 composite, a simple photochemical reduction process was used to deposit Ag nanoparticles onto the RGO–Bi 2 WO 6 composite in AgNO 3 aqueous solution under xenon lamp irradiation . Interestingly, the graphene sheet grafted Ag@ AgX (X = Cl, Br) hybrids could be constructed by directly photoreducing AgX/GO solid composites fabricated by the deposition‐precipitation method (as shown in Figure A), because AgX could be partially reduced through the photocorrosion . Moreover, the structure defects in RGO could be even utilized to spontaneously reduce the Ag + ions (Figure B) to construct the Ag/Ag 2 CO 3 ‐RGO nanocomposite (Figure C,D), because of the positive ∆ E between the two half reactions (reduction of Ag + ions and the oxidation of the defects).…”

Regulations of silver halide nanostructure and composites on photocatalysis

“…Besides providing these organic matter references, some representative parameters for photocatalysis evaluation have also been summarized and analyzed, such as the apparent rate constant (k app ) and total organic carbon (TOC). [240] benzene Ag/AgCl/TiO 2 /PM [289] acridine orange (AO) Ag@AgX (X = Cl, Br) [308] acid red G aqueous solution Bi 2 SiO 5 /AgI [268] The real-time concentration changes of organic pollutants during photocatalytic degradation are detected through their UV-visible absorbance. According to Lambert-Beer law, actual concentration changes of colored dye molecules (C/C 0 ) are directly proportional to their corresponding normalized UVvis absorption values (A/A 0 ).…”

“…The hybridization of AgX or Ag/AgX with other nonphotocatalytic materials (shown in Table 3) specially the carbon-based conductive matters has attracted extensive concerns due to their unique electronic properties and high specific surface area [306][307][308][309][310][311][312][313][314][315]. In hybridization aspect between AgX and photocatalytic substrates, the photocatalysis elevation is based on the Z-scheme heterogeneous structure formation in order to gain high charge separation efficiency [316][317][318][319][320][321].…”

Environmental Remediation Applications of Carbon Nanotubes and Graphene Oxide: Adsorption and Catalysis

“…Photocatalytic performance of the thus-prepared Ag@AgX@Graphene plasmonic photocatalysts for the degradation of the AO pollutant under sunlight irradiation (C). Reproduced with permission from [130]. Copyright Royal Society of Chemistry, 2013.…”