Water Splitting on Rutile TiO₂‐Based Photocatalysts

Abstract

Water splitting using a semiconductor photocatalyst with sunlight has long been viewed as a potential means of large-scale H production from renewable resources. Different from anatase TiO , rutile enables preferential water oxidation, which is useful for the construction of a Z-scheme water-splitting system. The combination of rutile TiO with a suitable H -evolution photocatalyst such as a Pt-loaded BaZrO -BaTaO N solid solution enables solar-driven water splitting into H and O . While rutile TiO is a wide-gap semiconductor with a bandgap of 3.0 eV, co-doping of rutile TiO with certain metal ions and/or nitrogen produces visible-light-driven photocatalysts, which are also useful as a component for water oxidation in visible-light-driven Z-scheme water splitting. The key to achieving highly efficient water oxidation is to maintain a charge balance of dopants in the rutile, because single doping typically produces trap states that capture photogenerated electrons and/or holes. Here we provide a concise summary of rutile TiO -based photocatalysts for water-splitting systems.

Enhanced water splitting through two-step photoexcitation by sunlight using tantalum/nitrogen-codoped rutile titania as a water oxidation photocatalyst

“…The photocatalytic splitting of water into H 2 and O 2 is one potential means of producing H 2 using solar energy. [1][2][3][4][5][6] Semiconductors capable of absorbing visible light have been extensively studied over the last half century as photocatalysts for water splitting, because visible light accounts for approximately one half of the energy contained in sunlight. [1][2][3][4][5][6] Various reaction schemes have been proposed for water splitting.…”

“…[1][2][3][4][5][6] Semiconductors capable of absorbing visible light have been extensively studied over the last half century as photocatalysts for water splitting, because visible light accounts for approximately one half of the energy contained in sunlight. [1][2][3][4][5][6] Various reaction schemes have been proposed for water splitting. Among these, the two-step photoexcitation system referred to as the Z-scheme, which uses two different semiconductor photocatalysts, is the most promising because it requires lower energy photons and allows the separation of the H 2 /O 2 mixture that is generated during the water splitting reaction.…”

“…Among these, the two-step photoexcitation system referred to as the Z-scheme, which uses two different semiconductor photocatalysts, is the most promising because it requires lower energy photons and allows the separation of the H 2 /O 2 mixture that is generated during the water splitting reaction. [4][5][6] In the Z-scheme process, the two semiconductors catalyze H 2 and O 2 evolution, while a redox shuttle reagent mediates electron transfer between the two materials (Scheme 1). Many semiconductors, including doped metal oxides, solid solutions and mixed anion compounds, have been assessed as visible light water-splitting photocatalysts applicable to either water reduction or oxidation in Z-scheme water splitting.…”

A C-Doped TiO2/Fe3O4 Nanocomposite for Photocatalytic Dye Degradation under Natural Sunlight Irradiation

“…Recently, TiO 2 -based photocatalysts have been used in several applications, such as antimicrobial activity [1], water splitting [2], hydrogen production [3], carbon dioxide reduction [4], organic pollutant degradation [5][6][7][8], solar cells [9][10][11], batteries [12], and super capacitors [13,14]. Currently, the search has intensified for an abundant, inexpensive, efficient, safe, and recyclable photocatalyst that can be used for degradation of organic contaminants, for instance, methyl orange (MO) in wastewater treatment and/or water purification.…”

Perovskite Oxide LaNiO3 Nanoparticles for Boosting H2 Evolution over Commercial CdS with Visible Light

“…[1][2][3][4][5] Semiconductor-mediated photocatalytic water splitting is one intriguing technique for producing clean hydrogen (H 2 ) energy. [15][16][17][18][19][20][21][22] However,t he efficiency realized so far can stilln ot meet the needs of commercial utilization, which is hindered mainly by the scarcity of affordable, efficient, and stable photocatalysts. [15][16][17][18][19][20][21][22] However,t he efficiency realized so far can stilln ot meet the needs of commercial utilization, which is hindered mainly by the scarcity of affordable, efficient, and stable photocatalysts.…”