Grape Seed Extract Assisted Synthesis of Dual-Functional Anatase TiO2 Decorated Reduced Graphene Oxide Composite for Supercapacitor Electrode Material and Visible Light Photocatalytic Degradation of Bromophenol Blue Dye

Cerium-based metal sulfide derived nanocomposite-embedded rGO as an efficient catalyst for photocatalytic application

Reduced graphene oxide (rGO) with metal sulfides is an efficient photocatalyst for treating textile effluent. Herein, a hydrothermal technique was used to synthesize transition metal sulfide with rGO nanocomposite. Under 120 min of sunlight exposure, the cerium-nickel sulfide/rGO nanocomposite (Ce₂S₃-NiS₂/rGO) photodegraded the methyl orange (MO) dye with an efficiency of 89.1% which is significantly higher than that of bare nickel sulfide (NiS₂) and cerium sulfide (Ce₂S₃) photocatalysts. Moreover, another model pollutant dye bromophenol blue (BP) was treated under the same experimental condition, and it has achieved about 84.2% degradation efficiency. The combination of NiS₂ and Ce₂S₃ improves the separation efficiency of photogenerated carriers, resulting in improved photocatalytic activity. In addition, ternary metal sulfide with rGO increases pollutant adsorption and electron-hole photogenerated pairs. Therefore, the mechanism of photocatalytic Ce₂S₃-NiS₂/rGO is investigated in detail. This research could pave the way for the development of capable and adaptable Ce₂S₃-NiS₂/rGO photocatalysts for environmental remediation.

Highly Efficient Solar Light Driven g-C3N4@Cs0.33WO3 Heterojunction for the Photodegradation of Colorless Antibiotics

This study facilitates the synthesis of a graphitic carbon nitride/cesium tungsten oxide (g-C₃N₄@Cs_0.33WO₃) heterojunction using a solvothermal method. The photocatalytic activities of the prepared samples were examined for the photodegradation of colorless antibiotics, namely tetracycline, enrofloxacin, and ciprofloxacin, as well as cationic and anionic dyes, such as methyl orange, rhodamine B, neutral red, and methylene blue, under full-spectrum solar light. We have purposely selected different kinds of wastewater pollutants of colorless antibiotics and cationic and anionic organic dyes to investigate the potential application of this heterojunction toward different groups of water pollutants. The results revealed that the g-C₃N₄@Cs_0.33WO₃ heterojunction showed an outstanding photocatalytic activity toward all the pollutants with concentrations of 20 ppm each at pH 3 by photocatalytically removing 97% of tetracycline within 3 h, 98% of enrofloxacin within 2 h, 97% of ciprofloxacin within 2.25 h, 98% of methylene blue in 1 h, 99% of rhodamine B within 2 h, 99% of neutral red in 1.25 h, and 95% of methyl orange in 2 h. These findings indicate that the developed photocatalyst possesses excellent photocatalytic properties toward seven different water pollutants that make it a universal photocatalyst. The developed g-C₃N₄@Cs_0.33WO₃ oxide heterojunction also presented a photocatalytic performance better than those of reported solar light active photocatalysts for photodegradation of rhodamine B and tetracycline. The efficient photocatalytic performance of the heterojunction can be ascribed to its extended light-absorbing ability, effective charge separation and fast charge transfer properties, and a high surface area. Moreover, an active species detection experiment also confirmed that superoxide radicals, hydroxyl radicals, and holes played significant roles in the photocatalysis of the organic dyes and tetracycline.

Construction of Spindle-Shaped Ti3+ Self-Doped TiO2 Photocatalysts Using Triethanolamine-Aqueous as the Medium and Its Photoelectrochemical Properties

To enhance the utilization efficiency of visible light and reduce the recombination of photogenerated electrons and holes, spindle-shaped TiO2 photocatalysts with different Ti3+ concentrations were fabricated by a simple solvothermal strategy using low-cost, environmentally friendly TiH2 and H2O2 as raw materials and triethanolamine-aqueous as the medium. The photocatalytic activities of the obtained photocatalysts were investigated in the presence of visible light. X-ray diffraction (XRD), Raman spectra, transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectra were applied to characterize the structure, morphologies, and chemical compositions of as-fabricated Ti3+ self-doped TiO2. The concentration of triethanolamine in the mixed solvent plays a significant role on the crystallinity, morphologies, and photocatalytic activities. The electron–hole separation efficiency was found to increase with the increase in the aspect ratio of as-fabricated Ti3+ self-doped TiO2, which was proved by transient photocurrent response and electrochemical impedance spectroscopy.

Graphene-Wine Waste Derived Carbon Composites for Advanced Supercapacitors

In this work, we investigate the potential of a novel carbon composite as an electrode for high-voltage electrochemical double-layer capacitors. The carbon composite was prepared following a sustainable synthetic approach that first involved the pyrolysis and then the activation of a precursor formed by winery wastes and graphene oxide. The composite prepared in this way shows a very high specific surface area (2467 m2·g−1) and an optimum pore size distribution for their use in supercapacitor electrodes. Graphene-biowaste-derived carbon composites are tested as active electrode materials in two different non-aqueous electrolytes, the ammonium salt-based conventional organic electrolyte and one imidazolium-based ionic liquid (1 M Et4NBF4/ACN and EMINTFSI). It was found that the presence of graphene oxide led to significant morphological and textural changes, which result in high-energy and power densities of ~27 W·h·kg−1 at 13,026 W·kg−1. Moreover, the devices assembled retain above 70% of the initial capacitance after 6000 cycles in the case of the organic electrolyte.

Nitrogen and Sulfur Co-Doped Graphene Quantum Dots Anchored TiO2 Nanocomposites for Enhanced Photocatalytic Activity

Herein, nitrogen (N) and sulfur (S) co-doped graphene quantum dots (GQDs) using different one-dimensional (1-D) carbon nanomaterials as precursors were synthesized, followed by heterojunction formation with TiO2. GQDs exhibit unlike physiochemical properties due to the disproportionate ratio of N and S heteroatoms and dissimilar reaction parameters. Tailored type-II band gap (Eg) alignment was formed with narrowed Eg value that improves photogenerated electron transfer due to π-conjugation. GQDs-TiO2 nanocomposites exhibit remarkably high methylene blue (MB) degradation up to 99.78% with 2.3–3 times elevated rate constants as compared with TiO2. CNF-GQDs-TiO2 demonstrates the fastest MB degradation (60 min) due to the synergistic effect of nitrogen and sulfur doping, and is considered the most stable photocatalyst among prepared nanocomposites as tested up to three cyclic runs. Whereas, C–O–Ti bonds were not only responsible for nanocomposites strengthening but also provide a charge transfer pathway. Moreover, charge transport behavior, generation of active species, and reaction mechanism were scrutinized via free-radical scavenger analysis.

Hepatoprotective and Antioxidant Capacity of Clerodendrum paniculatum Flower Extracts against Carbon Tetrachloride-Induced Hepatotoxicity in Rats

The aim of the presented work involves the isolation, characterization, and evaluation of hepatoprotective potential of Clerodendrum paniculatum flower extracts. For this purpose, petroleum ether, chloroform, ethyl acetate, alcohol, and water extracts of C. paniculatum flower were screened for the flavonoid and phenolic content and quantified. Various antioxidant activity assays including 2,2'-diphenyl-1-picrylhydrazyl (DPPH), nitric oxide (NO) radical scavenging, 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and reducing ability were carried out. Of the above methods, the alcoholic extract exhibited high antioxidant potential and was selected further for the hepatoprotective evaluations. Hepatoprotective evaluation of the alcoholic extract was carried out for carbon tetrachloride (CCl₄)-intoxicated model systems. Enzymes associated with liver functions were estimated, and histopathological evaluations were carried out to monitor the liver architecture. Prominently, reduced levels of various associated enzymes along with increased protein content were observed when the liver specimen was pretreated with the extract. Moreover, the liver architecture was almost comparable to that of the normal control group. The column chromatographic analysis of the extract revealed 13 fractions to possess high phenolics and flavonoid contents. The best two fractions were identified for in vitro hepatoprotective evaluation in the goat liver model. Furthermore, the GC-MS analyses of the fractions were carried out followed by a library search, to identify the constituents responsible for the hepatoprotective activity which revealed the presence of four major constituents-pilocarpine, glyceric acid, pangamic acid, and gallic acid. An in vitro hepatoprotective study of the isolated fractions showed better activity compared to the whole alcoholic extract, and the results were comparable to the normal group taken as a control. The investigations with an in vitro model suggest that the isolated fraction with rich flavonoid content showed better hepatoprotective activity. GC-MS analysis of the fractions that displayed good hepatoprotective activity suggested the presence of pilocarpine, glyceric acid, pangamic acid, and gallic acid, while HPTLC analysis revealed the presence of quercetin.

In situ synthesis of nanostructured Fe3O4@TiO2 composite grown on activated carbon cloth as a binder-free electrode for high performance supercapacitors

Transition metal oxide (TMO) nanomaterials with regular morphology have received widening research attention as electrode materials due to their improved electrochemical characteristics. In this study we present the successful fabrication of an Fe₃O₄/TiO₂ nanocomposite grown on a carbon cloth (Fe₃O₄/TiO₂@C) used as a high-efficiency electrochemical supercapacitor electrode. Flexible electrodes are directly used for asymmetric supercapacitors without any binder. The increased specific surface area of the TiO₂ nanorod arrays provides sufficient adsorption sites for Fe₃O₄ nanoparticles. An asymmetric supercapacitor composed of Fe₃O₄/TiO₂@C is tested in 1 M Na₂SO₃ electrolyte, and the synergistic effects of fast reversible Faraday reaction on the Fe₃O₄/TiO₂ surface and the highly conductive network formed by TiO₂@C help the electrode to achieve a high areal capacitance of 304.1 mF cm⁻² at a current density of 1 mA cm⁻² and excellent cycling stability with 90.7% capacitance retention at 5 mA cm⁻² after 10 000 cycles. As a result, novel synthesis of a binder-free Fe₃O₄/TiO₂@C electrode provides a feasible approach for developing competitive candidates in supercapacitor applications.

Transition metal oxide (TMO) nanomaterials with regular morphology have received widening research attention as electrode materials due to their improved electrochemical characteristics.