Synergy of metal and nonmetal dopants for visible-light photocatalysis: a case-study of Sn and N co-doped TiO₂

Abstract

This paper mainly focuses on the synergistic effect of Sn and N dopants to enhance the photocatalytic performance of anatase TiO2 under visible light or simulated solar light irradiation. The Sn and N co-doped TiO2 (SNT-x) photocatalysts were successfully prepared by the facile sol-gel method and the post-nitridation route in the temperature range of 400-550 °C. All the as-prepared samples were characterized in detail by X-ray diffraction, UV-vis diffuse reflectance spectroscopy, transmission electron microscopy, X-ray photoelectron and electron spin resonance spectroscopy and photoelectrochemical measurements. The characterization results reveal that the co-incorporation of Sn and N atoms remarkably modifies the electronic structure of TiO2, which gives rise to a prominent separation of photogenerated charge carriers and more efficient interfacial charge-transfer reactions in a photocatalytic process. The enhanced photocatalytic activity is attributed to the intensified active oxygen species including hydroxyl radicals (˙OH) and superoxide anion radicals (O2˙(-)) for degradation of organic pollutants. And the result of photocatalytic hydrogen production further confirms the existence of the synergistic effect in the SNT-x samples, because they exhibit higher photocatalytic activity than the sum of N/TiO2 and Sn/TiO2. This work provides a paradigm to consolidate the understanding of the synergistic effect of metal and non-metal co-doped TiO2 in domains of photocatalysis and photoelectrochemistry.

Facile synthesis of MoS 2 QDs/TiO 2 nanosheets via a self‐assembly strategy for enhanced photocatalytic hydrogen production

“…21-1272) of anatase TiO 2 . 40,41 Similarly, MoS 2 QDs/TiO 2 nanosheets only exhibit the characteristic diffraction peaks of TiO 2 with anatase phase, where no additional diffraction peak assigned to MoS 2 can be observed. It may be attributed to the low loading amount or high dispersion of MoS 2 on the surface of TiO 2 nanosheets.…”

“…Obviously, TiO 2 nanosheets display the characteristic diffraction peaks of anatase TiO 2 , which is consistent with the standard pattern (JCPDS No. 21‐1272) of anatase TiO 2 . Similarly, MoS 2 QDs/TiO 2 nanosheets only exhibit the characteristic diffraction peaks of TiO 2 with anatase phase, where no additional diffraction peak assigned to MoS 2 can be observed.…”

Construction of CdSe@TiO 2 core‐shell nanorod arrays by electrochemical deposition for efficient visible light photoelectrochemical performance

“…So far, considerable efforts have been contributed to the development of high‐efficiency and stable photoanodes . Titanium dioxide as a potential material has attracted extension attention for PEC field, attributing to its low cost, nontoxicity, strong redox capability, and extraordinary stability . In particular, one‐dimensional (1D) TiO 2 nanostructures, including nanowires, nanorods, nanobelts, and nanotubes, could enable the orientation of charge transport and enhance the charge transport efficiency; thus, they can be widely applied to photocatalysis and PEC water splitting .…”

“…9,10 Titanium dioxide as a potential material has attracted extension attention for PEC field, attributing to its low cost, nontoxicity, strong redox capability, and extraordinary stability. [11][12][13] In particular, one-dimensional (1D) TiO 2 nanostructures, including nanowires, nanorods, nanobelts, and nanotubes, could enable the orientation of charge transport and enhance the charge transport efficiency; thus, they can be widely applied to photocatalysis and PEC water splitting. 14,15 Nevertheless, their PEC water oxidation efficiency still is severely limited by the large bandgap of 3.0 eV for rutile and 3.2 eV for anatase and the high recombination rate of photogenerated charge carriers.…”

The Influence of Tin(II) Incorporation on Visible Light Absorption and Photocatalytic Activity in Defect‐Pyrochlores

“…[3] Metal sulphides usually have an arrower band gap than mosto xides. [9,10] The incorporation of divalent tin is of special interest, since the 5s 2 states of Sn 2 + possess am ore negative potentialc ompared to the oxygen 2p states that often form the valence band of transition metal oxides. [4] In the last years considerable effort was undertaken to develop new materials that are photocatalytically active in visible light, which composes am uch larger share of the solars pectrum, thus greatly enhancing the solar energy conversion efficiency.…”