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Bismuth vanadate (BiVO4) is one of the best bismuth-based semiconducting materials because of its narrow band gap energy, good visible light absorption, unique physical and chemical characteristics, and non-toxic nature. In addition, BiVO4 with different morphologies has been synthesized and exhibited excellent visible light photocatalytic efficiency in the degradation of various organic pollutants, including volatile organic compounds (VOCs). Nevertheless, the commercial scale utilization of BiVO4 is significantly limited because of the poor separation (faster recombination rate) and transport ability of photogenerated electron–hole pairs. So, engineering/modifications of BiVO4 materials are performed to enhance their structural, electronic, and morphological properties. Thus, this review article aims to provide a critical overview of advanced oxidation processes (AOPs), various semiconducting nanomaterials, BiVO4 synthesis methodologies, engineering of BiVO4 properties through making binary and ternary nanocomposites, and coupling with metals/non-metals and metal nanoparticles and the development of Z-scheme type nanocomposites, etc., and their visible light photocatalytic efficiency in VOCs degradation. In addition, future challenges and the way forward for improving the commercial-scale application of BiVO4-based semiconducting nanomaterials are also discussed. Thus, we hope that this review is a valuable resource for designing BiVO4-based nanocomposites with superior visible-light-driven photocatalytic efficiency in VOCs degradation. [ABSTRACT FROM AUTHOR]

The photocatalytic removal of water contaminants for ecological systems has become essential in the past few decades. Consequently, for commercialization, cost-efficient, earth-abundant and easy to synthesize photocatalysts for dye degradation are of urgent need. We have demonstrated a simple and feasible approach for fabricating TiO2–SnO2 nanocomposite photocatalysts via urea-assisted-thermal-decomposition with different mass ratios. The as-synthesized materials were characterized by different physicochemical techniques. The phase formation and crystallite size were calculated by using XRD. The STEM, UV-Vis, DRS, HR-TEM and EDS revealed the effective formation of the heterojunction between TiO2 and SnO2, and enrichment in the UV-absorption spectrum. All synthesized materials were used for the photocatalytic degradation of methyl orange (MO) under UV light. The optimized results of the TiO2–SnO2 nanocomposite showed excellent photostability and photocatalytic activity over a number of degradation-reaction cycles of methyl-orange (MO) dye under the illumination of ultraviolet light. In addition, the recent method has great potential to be applied as a proficient method for mixed-metal-oxide-nanocomposite synthesis. [ABSTRACT FROM AUTHOR]

Developing efficient, low-cost, and environment-friendly electrocatalysts for hydrogen generation is critical for lowering energy usage in electrochemical water splitting. Moreover, for commercialization, fabricating cost-efficient, earth-abundant electrocatalysts with superior characteristics is of urgent need. Towards this endeavor, we report the synthesis of PANI--MnMoO4 nanocomposites using a hydrothermal approach and an in situ polymerization method with various concentrations of MnMoO4. The fabricated nanocomposite electrocatalyst exhibits bifunctional electrocatalytic activity towards the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER) at a lower overpotential of 410 mV at 30 mA cm-2 and 155 mV at 10 mA cm-2, respectively in an alkaline electrolyte. Furthermore, while showing overall water splitting (OWS) performance, the optimized PM-10 (PANI--MnMoO4) electrode reveals the most outstanding OWS performance with a lower cell voltage of 1.65 V (vs. RHE) at a current density of 50 mA cm-2 with an excellent long-term cell resilience of 24 h. [ABSTRACT FROM AUTHOR]

Modulation of the structure, composition, and morphology through a simple refinement of the synthetic parameters is central to obtaining signature catalytic properties, enabling an understanding of the underlying growth and reaction mechanisms. In this study, a bismuth vanadate (BiVO4) model photocatalyst with several nanostructures (including pillar-like, dendrites, and microgranules) was fabricated by simple hydrothermal, solvothermal, and solid-state reaction (SSR) methods. As the solvothermal reaction temperature was increased, the tetragonal phase transformed into a monoclinic phase, and the inorganic nuclei interacted, self-assembled, and grew continuously to yield a well-defined architecture indicating the critical role of temperature in stabilizing the crystal structure and surface atomic features principally in an ethanol/water mixture. In contrast, conventional hydrothermal synthesis (only water as a solvent) resulted in single-phase BiVO4 pillars enriched with rough surfaces, sharp edges, and porous structures. The growth mechanism of the BiVO4 dendrites was investigated by the morphological evolutions from different reaction products obtained under different reaction conditions. BiVO4 has a bandgap energy in the visible spectral range (2.50–2.27 eV). Hence, BiVO4 architectures with exclusively controlled surfaces and crystal structures can be used as efficient photocatalysts to remove organic pollutants (methylene blue dye) in water. The solvothermally prepared BVO-SLR'24 with a mixed-phase (monoclinic and tetragonal zircon) structure exhibited superior photocatalytic activities for the decomposition of organic contaminants, which may be due to the unique connectivity between crystals, accelerated electron transfer, and heterojunction formation, compared to BiVO4 prepared with pure phase pillars and microgranules. This work highlights the significance of synthesis methodology and microstructural modification with the photophysical properties to reinvigorate the conventional design of visible-light-driven (VLD) photocatalysts. [ABSTRACT FROM AUTHOR]

Modulation of the structure, composition, and morphology through a simple refinement of the synthetic parameters is central to obtaining signature catalytic properties, enabling an understanding of the underlying growth and reaction mechanisms. In this study, a bismuth vanadate (BiVO4) model photocatalyst with several nanostructures (including pillar-like, dendrites, and microgranules) was fabricated by simple hydrothermal, solvothermal, and solid-state reaction (SSR) methods. As the solvothermal reaction temperature was increased, the tetragonal phase transformed into a monoclinic phase, and the inorganic nuclei interacted, self-assembled, and grew continuously to yield a well-defined architecture indicating the critical role of temperature in stabilizing the crystal structure and surface atomic features principally in an ethanol/water mixture. In contrast, conventional hydrothermal synthesis (only water as a solvent) resulted in single-phase BiVO4 pillars enriched with rough surfaces, sharp edges, and porous structures. The growth mechanism of the BiVO4 dendrites was investigated by the morphological evolutions from different reaction products obtained under different reaction conditions. BiVO4 has a bandgap energy in the visible spectral range (2.50–2.27 eV). Hence, BiVO4 architectures with exclusively controlled surfaces and crystal structures can be used as efficient photocatalysts to remove organic pollutants (methylene blue dye) in water. The solvothermally prepared BVO-SLR'24 with a mixed-phase (monoclinic and tetragonal zircon) structure exhibited superior photocatalytic activities for the decomposition of organic contaminants, which may be due to the unique connectivity between crystals, accelerated electron transfer, and heterojunction formation, compared to BiVO4 prepared with pure phase pillars and microgranules. This work highlights the significance of synthesis methodology and microstructural modification with the photophysical properties to reinvigorate the conventional design of visible-light-driven (VLD) photocatalysts. [ABSTRACT FROM AUTHOR]

Summary: Elemental doping promises an efficient strategy to modify and optimize the performance of metal oxide photoanodes. Herein, we introduce a simple hydrothermal method to fabricate In‐doped ZnO thin films on the fluorine‐doped tin oxide (FTO) to use as a photoanode for water splitting application. The effects of In‐doping on the structural, optical, morphological, and electrical properties of ZnO nanorods were studied. PEC results indicate that the 5% In doped ZnO photoanode determined an outstanding photocurrent density reached 0.42 mA/cm2 at 0.64 VAg/AgCl, which is four times higher than the undoped ZnO sample (0.1 mA/cm2). Furthermore, Ultraviolet‐visible spectroscopy (UV‐Vis) and photoluminescence spectroscopy (PL) studies showed a red‐shift in the band edge of doped samples compared to the pure samples, which indicate that the light absorption is enhanced. We find that the optimal doping of In (5%) leads to smaller charge transfer resistance and higher electron transfer rate as confirmed from EIS analysis. Therefore, fabricated In‐doped ZnO could be a favorable and potential photoelectrode for light‐harvesting and water splitting application. [ABSTRACT FROM AUTHOR]