Facets coupling of BiOBr-g-C3N4 composite photocatalyst for enhanced visible-light-driven photocatalytic activity

et al. 2017

Molecular Catalysis

a b s t r a c tIn this investigation, novel Ag/Bi 12 O 17 Cl 2 plasmonic composites with different Ag contents were constructed through a solvothermal and subsequent photoreduction route and fully characterized by a collection of analytical techniques. Spectroscopic results confirmed the presence and uniform dispersion of Ag nanoparticles on the 2D nanosheets of Bi 12 O 17 Cl 2 . The Ag content in composites exerted considerable influence on the extension of light-adsorption range and the enlargement of specific surface areas. The photocatalytic abilities of these Ag/Bi 12 O 17 Cl 2 composites were evaluated toward the degradation of rhodamine B (RhB) and 2,4-dichlorophenol (2,4-DCP) under the visible-light irradiation. The results demonstrated that the Ag/Bi 12 O 17 Cl 2 composites showed much higher photocatalytic efficiencies than that of pure Bi 12 O 17 Cl 2 , especially the sample with an optimal Ag content showing the best photocatalytic behavior among all tested samples. The remarkable enhancement of Ag/Bi 12 O 17 Cl 2 photocatalytic efficiency could be mainly attributed to the efficient charge separation that was induced by the localized surface plasmon resonance effect of metallic Ag, strong visible-light adsorption and the favorable morphology with enlarged specific surface areas. Eventually, the photocatalysis mechanism over Ag/Bi 12 O 17 Cl 2 composites was preliminarily proposed on the base of reactive species trapping experiments.

Section: Fig 3 Sem Images Of Composites Ab0 (A) and Ab4(b) And Thementioning

confidence: 99%

Section: Photocatalytic Activity Measurementmentioning

confidence: 99%

Ag/Bi12O17Cl2 composite: A case study of visible-light-driven plasmonic photocatalyst

et al. 2017

Molecular Catalysis

“…Specifically, 1.0 mM isopropanol alcohol (IPA) or disodium ethylenediaminetetraacetate (EDTA-2Na) was added to detect hydroxyl radicals ( • OH) or produced holes (h + ) [31]. 25 M nitroblue tetrazolium (NBT) was added in place of RhB to analyze superoxide radicals ( • O 2 − ) that might possibly generate during photocatalysis [32]. The ESR technique was further used to detect the presence of radicals • OH and • O 2 − in system.…”

Section: Photocatalytic Performancementioning

confidence: 99%

Enhanced visible-light-driven photocatalytic performance of mesoporous W-Ti-SBA-15 prepared through a facile hydrothermal route

Colloids and Surfaces A: Physicochemical and Engineering Aspect

et al. 2016

h i g h l i g h t s• A series of tungsten-titaniumcocontained SBA15 composites were fabricated by a simple synthetic route.• These samples showed enhanced catalytic performance in comparison to those comprising bare tungsten or titanium component.• The enhancement of photocatalytic behavior under visible-light irradiation was discussed. t r a c tA facile and one-step hydrothermal procedure was adopted to fabricate a series of W-Ti-SBA15 composites (WTS). These as-prepared composites were systematically characterized by a collection of analytic and spectroscopic techniques. It was found that dual phases of titanium and tungsten species coexisted in mesoporous structures of p6 mm hexagonal symmetry. In addition, these composites were visible-light responsive and exhibited enhanced photocatalytic capability toward degradation of Rhodamine B (RhB) and 2,4-dichlorophenol (2,4-DCP) upon visible-light irradiation in comparison to samples containing single component of titanium or tungsten species. Specifically, the best candidate, sample 8%WTS0.7, had the largest apparent reaction rate constant that was nearly 1.2, 2.1, 2.2, and 5.7 times as high as those of 8%WS, TS0.7, WO 3 /TiO 2 , and N-TiO 2 , respectively. The enhancement of photocatalytic performance was mainly attributed to the well-matched band structures of both components and strengthened visiblelight adsorption ability, originating from the combination of titania with highly acidic WO 3 in SBA15 matrix with large specific surface areas. Active radical species were detected by trapping experiments and a possible photocatalytic mechanism was thus proposed.

“…7A, there is almost no change in the degradation of RhB after involvement of IPA, indicating that Å OH radicals are not the dominant oxidative species. In addition, the transformation percentage of NBT can be omitted, revealing the absence of Å O 2 À radicals [38]. In contrast, the addition of EDTA-2Na can greatly restrain the photocatalytic performance, confirming that holes are major reactive species, instead of both OH and Å O 2 À radicals.…”

Section: Resultsmentioning

confidence: 99%

“…5 mM isopropanol (IPA) or disodium ethylenediaminetetraacetate (EDTA-2Na) was charged for trapping hydroxyl radicals ( Å OH) or produced holes (h + ) [37]. In addition, 25 lM nitroblue tetrazolium (NBT) was added replacing RhB to detect superoxide radicals ( Å O 2 À ) that might possibly generate during photocatalysis [38]. ESR signals of radicals spin-trapped by 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) were measured on a FA200 spectrometer.…”

Section: Photocatalytic Performancementioning

confidence: 99%

Synthesis, characterization, and visible-light-driven photocatalytic performance of W-SBA15

Journal of Colloid and Interface Science

et al. 2016

a b s t r a c tA series of tungsten-containing mesoporous SBA15 with different tungsten contents were prepared through a direct co-condensation sol-gel method and then analyzed by various techniques. XRD patterns revealed that the original mesoporous morphology was maintained after introducing tungsten species and forms of tungsten species were changed from incorporated tungsten to isolated tungsten species or low oligomeric tungsten oxide species, and finally to crystalline WO 3 with the increase of tungsten precursor content, which were also proven by HRTEM images, UV-Vis DRS, and FT-IR spectra. The W-SBA15 samples exhibited satisfactory photocatalytic performance toward degradation of dye Rhodamine B (RhB) and 2,4-dichlorophenol (2,4-DCP). In particular, the best candidate, sample 10%W-SBA15 showed an apparent reaction rate constant for RhB that was nearly 10 times as high as that of bulk WO 3 . The enhancement of photocatalytic capability was attributed to the mesoporous morphology with enlarged surface areas, negatively charged surface, and favorable tungsten forms such as incorporated tungsten, isolated tungsten or low oligomeric tungsten oxide species. In addition, active radicals trapping experiments and DMPO spin-trapping ESR spectra indicated that photogenerated holes were major oxidative species during photocatalysis.