Screening of photocatalysts by scanning electrochemical microscopy.
A method for rapid screening of photocatalysts employing a form of scanning electrochemical microscopy (SECM) is described. A piezoelectric dispenser was used to deposit arrays composed of approximately 300-microm-size photocatalyst spots with different compositions onto conducting glass, fluorine-doped tin oxide substrate. The scanning tip of the SECM was replaced by a fiber optic connected to a xenon lamp and was rapidly scanned over the array. In this arrangement, the photocatalytic performance of the spots was evaluated by measuring the photocurrent at the substrate of the array. A fiber optic with a ring electrode can also be used to electrochemically detect products of the photoreaction. Several iron oxide-based bimetallic oxide combinations were found to exhibit enhanced photocatalytic activity, when compared to pure alpha-Fe2O3. These combinations included iron-palladium, iron-europium, and iron-rubidium in specific ratios. A trimetallic bismuth-vanadium-zinc oxide combination was also found to show a higher photocurrent, by approximately 40%, compared to BiVO3.
Lee
Joowook
J
Center for Electrochemistry, Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
Ye
Heechang
H
Pan
Shanlin
S
Bard
Allen J
AJ
D001729:Bismuth / Q000737:chemistry*; D002384:Catalysis; D055664:Electrochemical Techniques / Q000379:methods; D005290:Ferric Compounds / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning / Q000379:methods*; D055668:Photochemical Processes; D012834:Silver / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D014025:Titanium / Q000737:chemistry; D014638:Vanadates / Q000737:chemistry*; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000737:chemistry*
D005290:Ferric Compounds; D018030:Silver Compounds; C091754:bismuth vanadium tetraoxide; C009495:titanium dioxide; C000499:ferric oxide; D012834:Silver; D014638:Vanadates; D014025:Titanium; C037548:silver chloride; D015034:Zinc Oxide; D001729:Bismuth