Rapid Screening of BiVO4-Based Photocatalysts by Scanning Electrochemical Microscopy (SECM) and Studies of Their Photoelectrochemical Properties

A picoliter solution dispenser was used to fabricate various n-type BiVO4 based photocatalyst arrays having different compositions and a scanning electrochemical microscopy (SECM) technique modified by replacing a normal ultramicroelectrode with an optical fiber was used for fast screening of the effective photocatalysts for Na2SO3 (as a sacrificial reductant) and water oxidation. Bi/V/W oxide with a ratio of 4 5.5 0.5 showed similar to 4 6x higher photocurrent than Bi/V oxide without W and this result was confirmed with bulk film studies. Preliminary characterization (XRD, XPS, and EIS) was also performed for these catalysts This material was tested for photoelectrochemical water oxidation with a Pt ring optical fiber to detect the product (O-2) of photoelectrochemical oxidation reaction