resumo
This work focuses on spectral sensitization of mesoporous TiO2 films and Nb-doped TiO2 films with polydisperse PbSe nanoparticles (TiO2/PbSe). For this, PbSe was electrochemically deposited from aqueous solution containing Pb2+ cations and SeO2. Chemical amount of electrodeposited PbSe was controlled by deposition time and impacted on the magnitude of sensitized photocurrents. The efficacy of different ions (S-n(2-); I-3(-); H2PO4-; N2H5+; SO32-; SCN-, SeSO32-) as hole scavengers for TiO2/PbSe photoanodes was assessed by dynamics of photocurrent in polarization measurements. Electrolyte of Na2SO3 and Na2SeSO3 is reported as an effective one to attain stable photocurrent. Photoelectrochemical cells with TiO2/PbSe photoanodes show solar to electricity conversion efficiency of 0.09%, in spectral region up to 700 nm for undoped TiO2. Enhancement of the photoresponse was achieved by different level of Nb doping into mesoporous TiO2 film. Extension of spectral response up to 800 nm and photocurrent conversion efficiency of 0.24% is observed for TiO2/PbSe photoanodes with 2.5 at% Nb-doped TiO2. Doping with Nb results in positive shift on electrochemical scale of conduction band of TiO2. It favors the collection of photoelectrons from PbSe nanoparticles that have light absorption in wider spectral region. (C) 2017 Elsevier Ltd. All rights reserved.
palavras-chave
LEAD SELENIDE NANOPARTICLES; QUANTUM DOTS; SOLAR-CELLS; THIN-FILMS; OPTICAL-PROPERTIES; ENVIRONMENTAL APPLICATIONS; ELECTRON INJECTION; MESOPOROUS TIO2; COLLOIDAL PBSE; PHOTOCATALYSIS
categoria
Electrochemistry
autores
Ivanou, DK; Ivanova, YA; Poznyak, SK; Starykevich, M; Ferreira, M; Mendes, A; Streltsov, EA
nossos autores
Maksim Starykevich
Investigador Júnior
Mário Guerreiro Silva Ferreira
Professor(a) Jubilado(a)
Yuliya Ivanova
Bolseiro de pós-Doutoramentoagradecimentos
This work was supported by the European Commission through the Seventh Framework Programme, the Specific Programme "Ideas" of the European Research Council for research and technological development as part of an Advanced Grant under grant agreement No 321315. The authors would like to acknowledge Jose Macaira Nogueira (LEPABE, Faculty of Engineering, University of Porto) for ALD deposition of TiO