title: Solution-processed, antimony-doped tin oxide colloid films enable high-performance TiO2 photoanodes for water splitting.
abstract: Photoelectrochemical (PEC) water splitting and solar fuels hold great promise for harvesting solar energy. TiO2-based photoelectrodes for water splitting have been intensively investigated since 1972. However, solar-to-fuel conversion efficiencies of TiO2 photoelectrodes are still far lower than theoretical values. This is partially due to the dilemma of a short minority carrier diffusion length, and long optical penetration depth, as well as inefficient electron collection. We report here the synthesis of TiO2 PEC electrodes by coating solution-processed antimony-doped tin oxide nanoparticle films (nanoATO) on FTO glass with TiO2 through atomic layer deposition. The conductive, porous nanoATO film-supported TiO2 electrodes, yielded a highest photocurrent density of 0.58 mA/cm(2) under AM 1.5G simulated sunlight of 100 mW/cm(2). This is approximately 3× the maximum photocurrent density of planar TiO2 PEC electrodes on FTO glass. The enhancement is ascribed to the conductive interconnected porous nanoATO film, which decouples the dimensions for light absorption and charge carrier diffusion while maintaining efficient electron collection. Transient photocurrent measurements showed that nanoATO films reduce charge recombination by accelerating transport of photoelectrons through the less defined conductive porous nanoATO network. Owing to the large band gap, scalable solution processed porous nanoATO films are promising as a framework to replace other conductive scaffolds for PEC electrodes.
authors.affiliation: Electrical and Computer Engineering Department, Duke University, Durham, North Carolina 27708, United States. qing.peng@duke.edu
authors.forename: Qing
authors.initials: Q
authors.lastname: Peng
authors.forename: Berç
authors.initials: B
authors.lastname: Kalanyan
authors.forename: Paul G
authors.initials: PG
authors.lastname: Hoertz
authors.forename: Andrew
authors.initials: A
authors.lastname: Miller
authors.forename: Do Han
authors.initials: DH
authors.lastname: Kim
authors.forename: Kenneth
authors.initials: K
authors.lastname: Hanson
authors.forename: Leila
authors.initials: L
authors.lastname: Alibabaei
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Meyer
authors.forename: Gregory N
authors.initials: GN
authors.lastname: Parsons
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Glass
mesh_terms: D003102:Colloids / Q000737:chemistry; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D053758:Nanoparticles / Q000737:chemistry; D012993:Solar Energy; D017971:Tin Compounds / Q000737:chemistry*; D014025:Titanium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D003102:Colloids; D017971:Tin Compounds; D014867:Water; C009495:titanium dioxide; D014025:Titanium; C045358:stannic oxide