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Anion doping into the oxygen site as a new plan for tuning the physical and chemical properties of metal oxides and adjusting their catalytic behavior has been studied. Herein, we report a Cl− anion-doped CuO (Cl-CuO) preparation method using deep eutectic solvents (DESs) as a green solvent, and the Cl-CuO/g-C3N4 heterostructure was successfully prepared in various weight ratios via a simple ultrasonication and mixing method for the oxygen evolution reaction (OER) in acidic media and the photocatalytic degradation of 4-nitrophenol. Cl− was doped into the CuO crystal lattice, as revealed by the XRD and XPS studies. The as-prepared Cl-CuO/g-C3N4 (1 : 2) exhibited a low overpotential of 0.77 V on the glassy carbon electrode with a current density of 33 mA cm−2 at 2.4 V for OER in an acidic solution. Also, about 92% degradation of 20 ppm of 4-nitrophenol was achieved for Cl-CuO/g-C3N4 (1 : 2) in 100 minutes under the irradiation of a 35 W Xe arc lamp. We also evaluated the effect of thermal energy on degradation kinetics by tuning the temperature, which led us to the quantification of various thermodynamic parameters. To the best of knowledge, this is one of the new methods of green synthesis to fabricate photocatalysts for energy and environmental studies. [ABSTRACT FROM AUTHOR]

An efficient Bi2WO6 catalyst with Co2+ substitution was synthesized via a facile hydrothermal route, and the materials were characterized by P-XRD, FT-IR, FE-SEM, XPS, DRS, BET and PL techniques. The obtained Co2+ substituted Bi2WO6 materials displayed high photocatalytic activity for organic dye degradation; 97.5% of the dye was photodegraded by 5 mol% of Co2+ substituted Bi2WO6 within 240 min induced by the visible light, which was remarkably better than the degradation of the bare and Co2+ substituted Bi2WO6 (1, 3, 7 and 9% Co2+ concentration). Based on the structural, optical and elemental characterization, it was determined that the substitution of the Co2+ ions in the Bi2WO6 lattice to replace the W6+ ion sites occurred without substantial changes in the crystal structure. The substituent Co2+ played a strategic role, which narrowed the band gap, leading to an enlargement in visible light absorption ability and suppressing the recombination of photogenerated electron–hole pairs credited to the Co2+ inner energy state. Additionally, the photocatalytic mechanism was elucidated by performing the radical trapping experiments, which disclosed that holes (h+) were the main species responsible for the RhB degradation. In addition, the stability of the catalysts was tested by performing recycling experiments. After the four repeating cycles, the degradation efficiency was not dramatically reduced. The results of this study disclosed that Co2+ substitution of W6+ may offer an alternative approach to enhance the Bi2WO6 photocatalytic activity. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DES) consisting of EG-(ChCl: C 2 H 6 O 2 ) and TU-(ChCl: CH 4 N 2 S) assisted synthesized BiOCl/BiVO 4 heterostructured catalyst studied for electrochemical uric acid (UA) sensor and tetracycline photocatalytic degradation. The chemical composition of the BiOCl/BiVO 4 catalyst was analyzed by X-ray photoelectron spectroscopy (XPS). UV-vis spectroscopy reveals increased absorption of visible light till the near-infrared region, which results in a narrowing of band gap energy from 2.3 eV to 2.2 eV for BiOCl/BiVO 4 -TU. Morphology of catalyst analyzed using field-emission scanning electron microscope (FE-SEM) and Transmission electron microscope (TEM) technique. Time-Resolved photoluminescence (TRPL) confirms an increased lifetime of e - /h + pair after heterostructure formation. The catalyst-modified glassy carbon electrode shows selectivity toward the detection of uric acid (UA). The limit of detection (LOD) is estimated to be 0.04688 μM for UA; also, interference and stability of catalyst were studied. Photocatalytic activity of the synthesized catalyst was investigated by degrading tetracycline (TC) antibiotic pollutants, and their intermediate product was analyzed by ion trap mass spectrometry (MS)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Antibiotics are essential medications for human and animal health, as they are used to battle urinary infections and bacterial diseases. Therefore, the rapid determination of antibiotic drugs in biological samples is necessary to address the current clinical challenge. Here, we developed a heterojunction ternary composite of BiOCl/BiVO 4 nanosheets enriched with graphene oxide (BiOCl/BiVO 4 @GO) for accurate and minimal-level detection of an antihistamine (promethazine hydrochloride, PMZ) in urine samples. The BiOCl/BiVO 4 nanosheets were prepared by a wet chemical approach using a deep eutectic green solvent. The spectroscopic and analytical methods verified the formation and interaction of the BiOCl/BiVO 4 @GO composite. Our results showed that the thoroughly exfoliated BiOCl/BiVO 4 @GO composite retained good electrical conductivity and fast charge transfer toward the electrode-electrolyte interface in neutral aqueous media. In addition, the experimental conditions were accurately optimized, and the BiOCl/BiVO 4 @GO composite showed excellent electrocatalytic activity toward the oxidation of PMZ. Indeed, the BiOCl/BiVO 4 @GO composite demonstrated a good linear response range (0.01-124.7 μM) and a detection level of 3.3 nM with a sensitivity of 1.586 μA μM -1  cm -2 . In addition, the BiOCl/BiVO 4 @GO composite had excellent storage stability, good reproducibility, and reliable selectivity. Finally, the BiOCl/BiVO 4 @GO displayed a desirable recovery level of PMZ in urine samples for real-time monitoring., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Anion doping into the oxygen site as a new plan for tuning the physical and chemical properties of metal oxides and adjusting their catalytic behavior has been studied. Herein, we report a Cl - anion-doped CuO (Cl-CuO) preparation method using deep eutectic solvents (DESs) as a green solvent, and the Cl-CuO/g-C 3 N 4 heterostructure was successfully prepared in various weight ratios via a simple ultrasonication and mixing method for the oxygen evolution reaction (OER) in acidic media and the photocatalytic degradation of 4-nitrophenol. Cl - was doped into the CuO crystal lattice, as revealed by the XRD and XPS studies. The as-prepared Cl-CuO/g-C 3 N 4 (1 : 2) exhibited a low overpotential of 0.77 V on the glassy carbon electrode with a current density of 33 mA cm -2 at 2.4 V for OER in an acidic solution. Also, about 92% degradation of 20 ppm of 4-nitrophenol was achieved for Cl-CuO/g-C 3 N 4 (1 : 2) in 100 minutes under the irradiation of a 35 W Xe arc lamp. We also evaluated the effect of thermal energy on degradation kinetics by tuning the temperature, which led us to the quantification of various thermodynamic parameters. To the best of knowledge, this is one of the new methods of green synthesis to fabricate photocatalysts for energy and environmental studies.

Graphene oxide-based composites have been developed as cheap and effective photocatalysts for dye degradation and water splitting applications. Herein, we report reduced graphene oxide (rGO)/Ag/Fe-doped TiO 2 that has been successfully prepared using a simple process. The resulting composites were characterized by a wide range of physicochemical techniques. The photocatalytic activities of the composite materials were studied under visible light supplied by a 35 W Xe arc lamp. The rGO/Ag/Fe-doped TiO 2 composite demonstrated excellent degradation of methylene blue (MB) in 150 min and 4-nitrophenol (4-NP) in 210 min under visible light irradiation, and trapping experiments were carried out to explain the mechanism of photocatalytic activity. Moreover, electrochemical studies were carried out to demonstrate the oxygen evolution reaction (OER) activity on rGO/Ag/Fe-doped TiO 2 in 1 M of H 2 SO 4 electrolyte, with a scan rate of 50 mV s -1 . The reductions in overpotential are due to the d-orbital splitting in Fe-doped TiO 2 and rGO as an electron collector and transporter., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)