Nanocrystalline immobilised ZnO photocatalyst for degradation of benzoic acid and methyl blue dye

• Published in: Materials research bulletin 2018-05, Vol.101, p.324-333
• Main Authors: Suryavanshi, R.D., Mohite, S.V., Bagade, A.A., Shaikh, S.K., Thorat, J.B., Rajpure, K.Y.
• Format: Article
• Language: English
• Subjects: BENZOIC ACID; CHEMICAL OXYGEN DEMAND; CRYSTAL STRUCTURE; DEPOSITION; ELECTROLYTES; MATERIALS SCIENCE; Methyl blue; METHYLENE BLUE; MORPHOLOGY; Mott-Schottky analysis; NANOSCIENCE AND NANOTECHNOLOGY; NANOSTRUCTURES; OPTICAL PROPERTIES; PHOTOCATALYSIS; POLYCRYSTALS; PYROLYSIS; SODIUM HYDROXIDES; Spray pyrolysis; THICKNESS; THIN FILMS; ULTRAVIOLET RADIATION; X-RAY DIFFRACTION; ZINC OXIDES; ZnO thin films
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2018.01.042

Hexagonal shaped microstructure synthesized by spray pyrolysis method for oxidative degradation of benzoic acid and methyl blue dye. [Display omitted] •ZnO thin films were successfully prepared with the help of chemical spray pyrolysis technique.•Study the effect of thickness variation(solution quantity) onto the various properties of film.•Film prepared at 1.65 μm thickness showsthe maximum photoelectrochemical performance in 0.1 M NaOH electrolyte.•The flat band potential of optimized ZnO thin film is –0.86 V/SCE.•Study degradation result of benzoic acidand methyl blue dye using ZnO photoelectrode under UV light illumination. ZnO thin films were deposited with different solution quantities using spray pyrolysis technique. The effect of thickness variations on photoelectrochemical (PEC), structural, morphological and optical properties are studied. PEC measurements showed maximum photo response about Isc = 0.485 mA and Voc = 632 mV at 1.65 μm film thickness. X-ray diffraction study confirms that the films are polycrystalline with hexagonal crystal structure. Hexagonal shaped grains are observed conformed from surface morphology. The estimated bandgap energy of ZnO films are varies between 3.23 to 3.29 eV. Finally large area (10 × 10 cm2) deposited ZnO photoelectrode were used to study the photocatalytic and photoelectrocatalytic degradation of benzoic acid (BA) and methyl blue (MB) dye under UV radiation. Photoelectrocatalytic degradation result shows 65.7% degradation of BA and for colorant organic compound such as MB dye is about 98.1% is possible. The mineralization of pollutants are studied by measuring chemical oxygen demand (COD) values.