000086446 001__ 86446
000086446 005__ 20200716101512.0
000086446 0247_ $$2doi$$a10.1016/j.electacta.2018.12.085
000086446 0248_ $$2sideral$$a110361
000086446 037__ $$aART-2019-110361
000086446 041__ $$aeng
000086446 100__ $$aHernández-Ferrer, J.
000086446 245__ $$aPhotoactivity improvement of TiO2 electrodes by thin hole transport layers of reduced graphene oxide
000086446 260__ $$c2019
000086446 5060_ $$aAccess copy available to the general public$$fUnrestricted
000086446 5203_ $$aNanostructured TiO2 and graphene-based materials constitute components of actual interest in devices related to solar energy conversion and storage. In this work, we show that a thin layer of electrochemically reduced graphene oxide (ECrGO), covering nanostructured TiO2 photoelectrodes, can significantly improve the photoactivity. In order to understand the working principle, ECrGO/TiO2 photoelectrodes with different ECrGO thicknesses were prepared and studied by a set of photoelectrochemical measurements. Methanol in alkaline conditions was employed as effective hole acceptor probe to elucidate the electronic phenomena in the electrode layers and interfaces. These studies underline the hole accepting properties of ECrGO and reveal the formation of a p-n junction at the interface between ECrGO and TiO2. It is shown for the first time that the resulting space charge region of about 10 nm defines the operational functionality of the ECrGO layer. Films thinner than the space charge region act as hole transport layer (HTL), which efficiently transfers holes to the liquid interface thus leading to enhanced photoactivity. Thicker films however act as hole blocking layer (HBL), resulting in a systematic decrease of the photoactivity. The finding of a thickness dependent threshold value for the operation of ECrGO as HTL and HBL is of general interest for the fabrication of optoelectronic devices with improved performance.
000086446 536__ $$9info:eu-repo/grantAgreement/ES/DGA/T03-17R$$9info:eu-repo/grantAgreement/ES/MINECO/BES-2014-068727$$9info:eu-repo/grantAgreement/ES/MINECO-FEDER/ENE2016-79282-C5-1-R
000086446 540__ $$9info:eu-repo/semantics/openAccess$$aAll rights reserved$$uhttp://www.europeana.eu/rights/rr-f/
000086446 590__ $$a6.215$$b2019
000086446 591__ $$aELECTROCHEMISTRY$$b5 / 27 = 0.185$$c2019$$dQ1$$eT1
000086446 592__ $$a1.467$$b2019
000086446 593__ $$aElectrochemistry$$c2019$$dQ1
000086446 593__ $$aChemical Engineering (miscellaneous)$$c2019$$dQ1
000086446 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion
000086446 700__ $$aAnsón-Casaos, A.
000086446 700__ $$aVíctor-Román, S.
000086446 700__ $$aSanahuja-Parejo, O.
000086446 700__ $$aMartínez, M.T.
000086446 700__ $$0(orcid)0000-0001-9814-0834$$aVillacampa, B.$$uUniversidad de Zaragoza
000086446 700__ $$aBenito, A.M.
000086446 700__ $$aMaser, W.K.
000086446 7102_ $$12003$$2395$$aUniversidad de Zaragoza$$bDpto. Física Materia Condensa.$$cÁrea Física Materia Condensada
000086446 773__ $$g298 (2019), 279-287$$pElectrochim. acta$$tElectrochimica Acta$$x0013-4686
000086446 8564_ $$s494526$$uhttps://zaguan.unizar.es/record/86446/files/texto_completo.pdf$$yPostprint
000086446 8564_ $$s194338$$uhttps://zaguan.unizar.es/record/86446/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint
000086446 909CO $$ooai:zaguan.unizar.es:86446$$particulos$$pdriver
000086446 951__ $$a2020-07-16-09:19:29
000086446 980__ $$aARTICLE