Bi 2 WO 6 microelectrode arrays on FTO glass substrates were fabricated by a picoliter solution dispensing technique using Bi(NO 3 ) 3 as the Bi source and (NH 4 ) 6 H 2 W 12 -O 40 as the W source in ethylene glycol. The scanning electrochemical microscope modified by using an optical fiber in place of an ultramicroelectrode was employed for rapid screening of the Bi 2 WO 6 arrays and to investigate the effect of 12 different dopants on the photocatalytic oxidation of SO 3 2− . Among the different dopant compositions, addition of 12% Zn showed a photocurrent enhancement of up to 80% compared with that of the pure Bi 2 WO 6 . This result was further confirmed with bulk electrode studies for SO 3 2− and water oxidation. UV− vis absorption, electrochemical impedance spectroscopy, scanning electron microscopy, and X-ray diffraction studies were carried out with the photocatalysts to elucidate the role of Zn in the bulk semiconductors. Absorbed photon-to-current efficiency and incident photon-to-current efficiency determinations further confirm the enhancement of photoelectrochemical behavior upon addition of Zn to Bi 2 WO 6 photocatalysts.

Herein, we report the synthesis and photoelectrochemical characterizations of n-type Fe–V-oxide semiconductors thin film via drop cast method in different proportions onto indium tin oxide coated glass followed by annealing in air at 500 °C for 3 h.

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Arc thermal metal spray coating provides excellent corrosion, erosion and wear resistance to steel substrates. This paper incorporates some results of aluminum coating applied by this method on plain carbon steel. Thereafter, coated panels were exposed to an environment known to form stable corrosion products with aluminum. The coated panels were immersed in Society of Automotive Engineers (SAE) J2334 for different periods of time. This solution consists of an aqueous solution of NaCl, CaCl 2 and NaHCO 3 . Various electrochemical techniques, i.e., corrosion potential-time, electrochemical impedance spectroscopy (EIS) and the potentiodynamic were used to determine the performance of stimulants in improving the properties of the coating. EIS studies revealed the kinetics and mechanism of corrosion and potentiodynamic attributed the formation of a passive film, which stifles the penetration of aggressive ions towards the substrate. The corrosion products that formed on the coating surface, identified using Raman spectroscopy, were Dawsonite (NaAlCO 3 (OH) 2 ) and Al(OH) 3 . These compounds of aluminum are very sparingly soluble in aqueous solution and protect the substrate from pitting and uniform corrosion. The morphology and composition of corrosion products determined by scanning electron microscopy and energy dispersive X-ray analyses indicated that the environment plays a decisive role in improving the corrosion resistance of aluminum coating.