The need for stable oxide-based semiconductors with a narrow band gap, able to maximize the exploitation of the visible light portion of the solar spectrum, is a challenging issue for photoelectrocatalytic (PEC) applications. In the present work, CuW1−xMoxO4 (Eg = 2.0 eV for x = 0.5), which exhibits a significantly reduced optical band gap Eg compared with isostructural CuWO4 (Eg = 2.3 eV), was investigated as a photoactive material for the preparation of photoanodes. CuW0.5Mo0.5O4 electrodes with different thicknesses (80−530 nm), prepared by a simple solution-based process in the form of multilayer films, effectively exhibit visible light photoactivity up to 650 nm (i.e., extended compared with CuWO4 photoanodes prepared by the same way). Furthermore, the systematic investigation on the effects on photoactivity of the CuW0.5Mo0.5O4 layer thickness evidenced that long-wavelength photons can better be exploited by thicker electrodes. PEC measurements in the presence of NaNO2, acting as a suitable hole scavenger ensuring enhanced photocurrent generation compared with that of water oxidation while minimizing dark currents, allowed us to elucidate the role that molybdenum incorporation plays on the charge separation efficiency in the bulk and on the charge injection efficiency at the photoanode surface. The adopted Mo for W substitution increases the visible light photoactivity of copper tungstate toward improved exploitation and storage of visible light into chemical energy via photoelectrocatalysis.
Effective Visible Light Exploitation by Copper Molybdo-tungstate Photoanodes / A. Polo, C. Nomellini, I. Grigioni, M.V. Dozzi, E. Selli. - In: ACS APPLIED ENERGY MATERIALS. - ISSN 2574-0962. - 2020:3(2020 Jun 08), pp. 6956-6964.
|Titolo:||Effective Visible Light Exploitation by Copper Molybdo-tungstate Photoanodes|
POLO, ANNALISA (Primo) [Writing – Original Draft Preparation]
NOMELLINI, CHIARA (Secondo) [Investigation]
GRIGIONI, IVAN [Membro del Collaboration Group]
DOZZI, MARIA VITTORIA (Penultimo) [Supervision]
SELLI, ELENA (Ultimo) [Writing – Review & Editing] (Corresponding)
|Parole Chiave:||Mo-modified CuWO4, band gap reduction, extended visible light photoactivity, photoelectrocatalysis, photoanode, charge separation|
|Settore Scientifico Disciplinare:||Settore CHIM/02 - Chimica Fisica|
|Progetto:||Photoelectrochemical Solar Light Conversion into Fuels on Colloidal Quantum Dots Based Photoanodes (QuantumSolarFuels)|
Laboratorio multifunzionale e centro di formazione per la caratterizzazione e la sperimentazione preapplicativa di smart materials
|Data di pubblicazione:||8-giu-2020|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1021/acsaem.0c01021|
|Appare nelle tipologie:||01 - Articolo su periodico|