Effects of citric acid and urea on the structural and morphological characteristics of BiVO4 synthesized by the sol–gel combustion method

Abstract

Micro-sized spherical BiVO 4 photocatalysts composed of nanoparticles were synthesized by the sol-gel combustion method. The effects of citric acid and urea on the structural and morphological characteristics of samples were studied by X-ray diffraction, field emission scanning electron microscopy, N 2 adsorption and desorption and UV-Vis spectroscopy. The photocatalytic activity was evaluated by the photocatalytic degradation of rhodamine B under visible light. The results showed the sphere-shaped BiVO 4 sample to have excellent photocatalytic performance compared with the bulk sample prepared by solidstate reaction. This enhancement could be attributed to the special spherical morphology, which enhanced the absorption ability, increased the separation efficiency of photon-generated carriers and improved surface reaction sites for consumption of photon-generated carriers. Graphical Abstract Uniform micro-sized spherical BiVO 4 samples composed of nanoparticles were successfully synthesized by the sol-gel combustion method. The relationships between the morphologies and citric acid with urea contents were studied by using the field emission scanning electron microscopy (FE-SEM) technology.

Superior visible light photocatalytic performance of reticular BiVO4 synthesized via a modified sol–gel method

“…All samples exhibit absorption in the visible light range and the steep absorbance edges of all spectra indicate that the visible light absorption is not due to the transition from impurity levels but the band gap transition. 34 The band gap energies ( E g ) of the prepared samples can be calculated from the UV-vis absorption spectra data using the following formula: αhν = A ( hν − E g ) n /2 , where α , ν , A and E g are the absorption coefficient, the light frequency, a constant and the band gap energy, respectively. The value for n is determined by the type of optical transition of a semiconductor ( n = 1 for direct transition and n = 4 for indirect transition).…”

Easy Synthesis of BiVO4 for Photocatalytic Overall Water Splitting

“…It is well known that crystallinity is an important factor to influence photocatalytic activity. Several routes were taken to prepare the BiVO 4 photocatalyst via the wet chemical route, including the solvothermal method, sol–gel synthesis, and hydrothermal synthesis. − Morphology control of the BiVO 4 photocatalyst, such as nanotubes, nanoribbons, nanorods, nanofibers, and nanoplates, is extensively studied and indicates that the morphology of the BiVO 4 photocatalyst is a crucial factor for characteristic properties of BiVO 4 . Particularly, the hydrothermal method had been used to synthesize structure-controlled and highly crystalline nanomaterials.…”

Light‐Driven Micromotors to Dissociate Protein Aggregates That Cause Neurodegenerative Diseases

“…Interestingly, concave defects with less than ≈2 µm diameter were also noticed (see Figure S2 in the Supporting Information for further details). Thus, a very unique morphology for round-shaped BiVO 4based materials was revealed that is different from the typical solid [22][23][24] or hollow [25][26][27] spheres. Moreover, nitrogen adsorption-desorption measurements were run as well in order to get further insight into their specific surface area (Figure S3, Supporting Information).…”