Photocatalytic organic degradation over W-rich and Cu-rich CuWO<sub>4</sub> under UV and visible light

Chen, Haihang; Xu, Yiming

doi:10.1039/c4ra13952f

Cited by 42 publications

(34 citation statements)

References 29 publications

(36 reference statements)

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“…BET surface area of CWO‐NPs was investigated using N 2 adsorption−desorption isotherm as shown in Figure d. Surface area of CWO‐NPs was found to be ∼12.20 m 2 /g which nearly consistent with previous reports at similar firing conditions …”

Section: Resultssupporting

confidence: 86%

Molten Salts Derived Copper Tungstate Nanoparticles as Bifunctional Electro‐Catalysts for Electrolysis of Water and Supercapacitor Applications

et al. 2018

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Herein, we report molten salts derived, cube‐shaped CuWO4 nanoparticles (50±5 nm) as multi‐functional catalysts in electrochemical and photo‐electrochemical studies. The formation of pure phase cube‐shaped CuWO4 nanoparticles (CWO‐NPs) is analyzed by X‐ray diffraction, Raman spectroscopy, X‐ray photo‐electron spectroscopy (XPS) and field‐emission electron microscopy (FE‐SEM and FE‐TEM). CWO‐NPs show remarkable bi‐functional electro‐catalytic behavior for the oxygen evolution (OER) and oxygen reduction reactions (ORR) in 1.0 M KOH electrolyte solution. Polarization studies of CWO‐NPs exhibit low over‐potential (∼260 mV) at 1 mA/cm2 and low Tafel slope value (∼190 mV/dec) for OER compared to bulk or other oxides. Polarization studies with controlled electrode rotation reveal a four‐electron pathway for the water electrolysis reaction for OER/ORR. In addition, CWO‐NPs show promising capacitive behavior with specific capacitance values of ∼230 F/g using 1 M KOH electrolyte. Galvanostatic charge‐discharge (GCD) studies of CWO‐NPs displays low energy loss during discharge time for 50 segments. To further investigate the potential for industrial applications, the stability of the electrodes is also examined using chrono‐amperometry (CA) at fixed potential, chrono‐potentiometry (CP) at fixed current density, and cyclic voltammetry (CV) with 50 cycles.

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Section: Resultssupporting

confidence: 86%

Molten Salts Derived Copper Tungstate Nanoparticles as Bifunctional Electro‐Catalysts for Electrolysis of Water and Supercapacitor Applications

et al. 2018

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“…The main peak of O1 s is observed at 530.3 eV and it is deconvoluted at 530.3 eV belongs to

{normalW normalO}_{3}

and at 530.9 eV belongs to

{C u}_{2} O

. Similarly, the Cu2 p (Figure B(d)) is shown at 932.5 and 952.2 eV due to

{C u}_{2} normalO

and the remaining peaks are shown at 934.1, 943.7, 953.9 and 962.1 eV due to

{normalC normalu normalW normalO}_{4}

. The binding energy of Cu2p 3/2 (932.5 eV) is slightly higher (instead of 932.2 eV for Cu + ) indicates the presence of Cu 2+ in the

{C u}_{2} O

lattice as p ‐type nature.…”

Section: Resultsmentioning

confidence: 89%

“…High resolution XPS patterns were also recorded for Cu ( 2p ), W ( 4 f ) and O ( 1 s ) with scan rate of 0.025 eV, time per step of 50 ms with 10 cycles of scanning. In Figure A(b), the peaks observed at 35.4, 37.6 and 41.3 eV due to the binding energies of W( 4f 7/2 ), W( 4f 5/2 ) and W( 5p 3/2 ) respectively, of W 6+ state . In Figure A(c), the main peak is shown at 530.5 eV for O ( 1 s ) and it can be deconvoluted into two peaks with broad at 530.3 and tail at 530.95 eV are assigned to the Cu−O of CuO and W−O of

{normalW normalO}_{3}

respectively ,.…”

Section: Resultsmentioning

confidence: 94%

“…The CuO is a stable photocatalyst. Chen and Xu have been reported that the heterostuctured CuWO 4 /WO 3 and CuWO 4 /CuO nanocomposites formed by annealing the hydrothermally as‐prepared particles . They showed more photocatalytic activity and photocurrent generation than the both bare photocatalysts and physically prepared nanocomposites.…”

Section: Introductionmentioning

confidence: 99%

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Preparation of Bifunctional CuWO₄‐Based Heterostructure Nanocomposites for Noble‐Metal‐Free Photocatalysts

2017

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This article describes the preparation of copper tungstate (normalCnormalunormalWnormalO4 )‐based heterostructured nanocomposites by facile two‐step polyol assisted hydrothermal‐annealed process. A series of characterization techniques (FESEM, EDS, HRTEM, XPS, XRD and FTIR etc.) were confirmed the formation of type‐I(CuWO4/WO3·0.33H2O, CuWO4/WO3 ) and type‐II (CuWO4/Cu2O,CuWO4/Cu2O/normalCnormalunormalO,CuWO4/normalCnormalunormalO) heterojunction as function of pH and annealing temperatures. Also WO3·0.33H2O , normalWnormalO3 , Cu2O , Cu2O/normalCnormalunormalO and CuO were found as secondary phases with normalCnormalunormalWnormalO4 . These nanocomposites exhibited the enhanced visible light absorption and the band gap (ca. 1.7 eV) of normalCnormalunormalWnormalO4 is smaller than the early reported value (2.1‐2.3 eV). In photocatalytic degradation, the normalCnormalunormalWnormalO4 /Cu2O/normalCnormalunormalO and CuWO4/WO3·0.33H2O were showed 1.66 fold times higher and nearly equal apparent rate constant respectively than that of normalCnormalunormalWnormalO4 . In photoelectrochemical (PEC) studies, the CuWO4/Cu2O , normalCnormalunormalWnormalO4 /Cu2O/normalCnormalunormalO , CuWO4/WO3 and CuWO4/normalCnormalunormalO nanocomposites showed more photocurrent density of 3.5, 2.2, 0.71 and 0.41 mA/cm2 at 1.23 VRHE respectively than CuWO4. The existence of dual co‐catalysts (Cu2O and CuO) with CuWO4, strongly promote the electron‐hole pair separation and migration. Among the nanocomposite, the CuWO4/normalCnormalunormalO was showed the similar static photocurrent as that of normalCnormalunormalWnormalO4 under 1 Sun illumination. The advantage of present work is noble‐metal‐free photocatalysts prepared with binder free, less time, low energy consumption and cost, and environmental benign.

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“…For the XPS Fe 2p spectra of the Fe8/AC sample, the peaks of Fe 2p 3/2 were found at the binding energy of 709.8 and 712.6 eV before SO 2 removal. 52,53 For the XPS spectra of Ni 2p of the Ni/AC sample, the Ni 2p 3/2 main peaks were found at the binding energy of 854.8 and 861.2 eV, which were ascribed to Ni 2+ of NiO 54 and the satellite peak of NiO, 55 respectively. 11 For the XPS spectra of Co 2p of the Co16/AC sample, the main peak of Co 2p 3/2 was centered at 780.2 eV, which was ascribed to Co 2+ of CoO.…”

Section: Metal Phase On Activated Coke Before Desulphurizationmentioning

confidence: 98%

The effects of metal oxide blended activated coke on flue gas desulphurization

et al. 2016

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The objective of this study was to investigate the possibility of using some natural minerals or industrial waste containing some metal oxides to prepare modified activated coke (M/AC) for flue gas desulphurization. The metal oxides, i.e. Fe 2 O 3 , Co 2 O 3 , CuO and Ni 2 O 3 , were used as additives to prepare M/AC by a blending method. The results show that the M/AC could effectively improve desulphurization performance, and the highest sulphur capacity was obtained at 143 mg g À1 for the Ni/AC sample with a blending ratio of 12 wt%, which was higher than that of the blank sample (97 mg g À1 ). The addition of metal oxides by the blending method could affect the textural properties of M/AC evidently and the influence was different with different metal oxides and blending ratios. On the other hand, M/AC samples have higher contents of oxygen-containing functional groups, with the highest for the Ni/AC sample, and have higher contents of p-p* transition groups, compared with blank activated coke. The metal oxides loaded on the M/AC were mainly transformed to metallic particles during the activation process, and to metal sulfate and partially metal oxides after the desulphurization process. † Electronic supplementary information (ESI) available: Fig. S1 shows the breakthrough curves of the metal oxides for ue gas desulphurization. Fig. S2 shows the overall XPS spectrum of prepared activated coke. Fig. S3 shows the binding energy patterns of C 1s for prepared activated cokes. See

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Photocatalytic organic degradation over W-rich and Cu-rich CuWO₄ under UV and visible light

Abstract: Cu-rich CuWO4 prepared at pH 8.5 and 600 °C was more active than other samples for organic degradation under visible light.

Cited by 42 publications

References 29 publications

Molten Salts Derived Copper Tungstate Nanoparticles as Bifunctional Electro‐Catalysts for Electrolysis of Water and Supercapacitor Applications

Molten Salts Derived Copper Tungstate Nanoparticles as Bifunctional Electro‐Catalysts for Electrolysis of Water and Supercapacitor Applications

Preparation of Bifunctional CuWO₄‐Based Heterostructure Nanocomposites for Noble‐Metal‐Free Photocatalysts

The effects of metal oxide blended activated coke on flue gas desulphurization

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Photocatalytic organic degradation over W-rich and Cu-rich CuWO4 under UV and visible light

Abstract: Cu-rich CuWO4 prepared at pH 8.5 and 600 °C was more active than other samples for organic degradation under visible light.

Cited by 42 publications

References 29 publications

Molten Salts Derived Copper Tungstate Nanoparticles as Bifunctional Electro‐Catalysts for Electrolysis of Water and Supercapacitor Applications

Molten Salts Derived Copper Tungstate Nanoparticles as Bifunctional Electro‐Catalysts for Electrolysis of Water and Supercapacitor Applications

Preparation of Bifunctional CuWO4‐Based Heterostructure Nanocomposites for Noble‐Metal‐Free Photocatalysts

The effects of metal oxide blended activated coke on flue gas desulphurization

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Photocatalytic organic degradation over W-rich and Cu-rich CuWO₄ under UV and visible light

Preparation of Bifunctional CuWO₄‐Based Heterostructure Nanocomposites for Noble‐Metal‐Free Photocatalysts