Origin of the overall water splitting activity over Rh/Cr2O3@ anatase TiO2 following UV-pretreatment

Sudrajat, Hanggara; Babel, Sandhya; Hartuti, Sri; Phanthuwongpakdee, Jakkapon; Laohhasurayotin, Kritapas; Nguyen, Truong Khang; Tong, Hien D.

doi:10.1016/j.ijhydene.2021.07.002

Cited by 5 publications

(5 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1(B)), demonstrating the cocatalyst photostability. Based on this finding, we expect that Earthabundant, first-row transition metals, such as the here developed mix-oxide of Ni, can potentially replace noble-metal co-catalysts, such as Ru, 28 Pd, 29 Pt 30 and Rh, 31 with comparable performances.…”

Section: Resultsmentioning

confidence: 75%

Critical Role of the NiO–Ni(OH)₂ Species Loaded Onto TiO₂ Photocatalyst in the Enhancement of H₂ Evolution Activity

Sudrajat¹,

Susanti²

2023

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

One of the bottlenecks in photocatalysis is to obtain reasonably cheap co-catalysts beneficially contributing to efficient photophysical and photochemical processess. Herein, we prepare a co-catalyst system consisting of Ni species embedded in anatase TiO2. We focus on clarifying its role in regulating electron behavior, and hence, photocatalytic activity. Based on the transmission electron microscopy, X-ray absorption near-edge structure, and X-ray absorption fine structure, the surface-loaded Ni species are found to exist as crystalline NiO, together with a small fraction of amorphous Ni(OH)2. Using a combination of transient microwave conductivity and static infrared absorption spectroscopy, we show that electron transfer to the Ni species instead of electron trapping by structural defects, such as oxygen vacancies or reduced titanium cations, is key mechanism responsible for the prolonged lifetime of photoexcited electrons. The prolonged electron lifetime due to an efficient electron extractionby the Ni species are behind the increased H2 evolution activity. We demonstrate that the NiO-Ni(OH)2 co-catalyst system, which works as a H2 evolution site, is auspicious to make photoexcited electrons abundantly available on the surface by localizing them, and thus, readily accessible for the desired surface reactions.

show abstract

Section: Resultsmentioning

confidence: 75%

Critical Role of the NiO–Ni(OH)₂ Species Loaded Onto TiO₂ Photocatalyst in the Enhancement of H₂ Evolution Activity

Sudrajat¹,

Susanti²

2023

J. Electrochem. Soc.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In addition, longrange order characterization techniques, such as x-ray diffraction, are incapable of recognizing impurities present in trace concentrations within the matrix. It can be seen in figure S2 that the chemical reduction with NaBH 4 does not change the diffraction patterns of TiO 2 , which is present as an anatase polymorph [4,5,[46][47][48]. There are also no impurities present in the examined samples, as indicated by the absence of any extra peaks besides the diffraction peaks of the characteristic anatase TiO 2 .…”

Section: Defects Responsible For Improved Photoactivitymentioning

confidence: 88%

“…Titanium dioxide, TiO 2 , is considered as the benchmark for a diverse range of photoredox reactions to convert stable molecules, such as H 2 O and CO 2 , into clean-burning energy carriers and industrially relevant chemical feedstocks [1][2][3][4][5]. For real-setting applications, the candidate must be sufficiently photoactive and photostable.…”

Section: Introductionmentioning

confidence: 99%

Reduced TiO₂ with prolonged electron lifetime for improving photocatalytic water reduction activity

Sudrajat

Susanti

Hartuti

2023

J. Phys.: Condens. Matter

Self Cite

View full text Add to dashboard Cite

The reduction of anatase TiO2 with NaBH4 under argon atmosphere at a high temperature resulted in a longer electron lifetime and a larger electron population. The reduced gray anatase sample with disorder layer showed a higher evolution rate of H2 (130.2 μmol h−1 g−1) compared to pristine TiO2 (24.1 μmol h−1 g−1) in the presence of Pt co-catalyst in an aqueous glucose solution under exposure to ultraviolet light (λ ⩽ 400 nm). Ti3+ and oxygen vacancy defects were proposed to exist in the reduced TiO2. A continuum tail forms above the valence band edge top as a result of these two defects, which contribute to the lattice disorder. This is presumably also the case with the conduction band, which has a continuum tail composed of mid-gap states as a result of the defects. The Ti3+ and oxygen vacancy defects operate as shallow traps for photoexcited electrons, thereby preventing recombination. Since the defects are primarily located at the surface, i.e. in the disorder layer, the photoexcited electrons in shallow traps hence become readily available for the reduction of H3O+ into H2. The prolonged electron lifetime increases the photoexcited electron population in the reduced TiO2, resulting in enhanced water reduction activity.

show abstract

“…Several factors affect anatase TiO 2 photoactivity, such as crystal size, specific surface area, and crystallinity [14][15][16]. The performance of the TiO 2 was optimized by doping [17][18][19][20], loading [21,22], and thin-film preparation [23,24]. Available studies indicated that some ions could enter the lattice as substitutional or interstitial; the titanium ions are substituted by metal ions in the crystal lattices.…”

Section: Introductionmentioning

confidence: 99%

Significantly Enhanced Self-Cleaning Capability in Anatase TiO2 for the Bleaching of Organic Dyes and Glazes

Zhao,

Cao,

Bao

et al. 2023

Inorganics

View full text Add to dashboard Cite

In this study, the Mg2+-doped anatase TiO2 phase was synthesized via the solvothermal method by changing the ratio of deionized water and absolute ethanol Vwater/Vethanol). This enhances the bleaching efficiency under visible light. The crystal structure, morphology, and photocatalytic properties of Mg-doped TiO2 were characterized by X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscopy, N2 adsorption-desorption, UV-Vis spectroscopy analysis, etc. Results showed that the photocatalytic activity of the Mg2+-doped TiO2 sample was effectively improved, and the morphology, specific surface area, and porosity of TiO2 could be controlled by Vwater/Vethanol. Compared with the Mg-undoped TiO2 sample, Mg-doped TiO2 samples have higher photocatalytic properties due to pure anatase phase formation. The Mg-doped TiO2 sample was synthesized at Vwater/Vethanol of 12.5:2.5, which has the highest bleaching rate of 99.5% for the rhodamine B dye during 80 min under visible light. Adding Mg2+-doped TiO2 into the phase-separated glaze is an essential factor for enhancing the self-cleaning capability. The glaze samples fired at 1180 °C achieved a water contact angle of 5.623° at room temperature and had high stain resistance (the blot floats as a whole after meeting the water).

show abstract

Origin of the overall water splitting activity over Rh/Cr2O3@ anatase TiO2 following UV-pretreatment

Cited by 5 publications

References 55 publications

Critical Role of the NiO–Ni(OH)₂ Species Loaded Onto TiO₂ Photocatalyst in the Enhancement of H₂ Evolution Activity

Critical Role of the NiO–Ni(OH)₂ Species Loaded Onto TiO₂ Photocatalyst in the Enhancement of H₂ Evolution Activity

Reduced TiO₂ with prolonged electron lifetime for improving photocatalytic water reduction activity

Significantly Enhanced Self-Cleaning Capability in Anatase TiO2 for the Bleaching of Organic Dyes and Glazes

Contact Info

Product

Resources

About

Origin of the overall water splitting activity over Rh/Cr2O3@ anatase TiO2 following UV-pretreatment

Cited by 5 publications

References 55 publications

Critical Role of the NiO–Ni(OH)2 Species Loaded Onto TiO2 Photocatalyst in the Enhancement of H2 Evolution Activity

Critical Role of the NiO–Ni(OH)2 Species Loaded Onto TiO2 Photocatalyst in the Enhancement of H2 Evolution Activity

Reduced TiO2 with prolonged electron lifetime for improving photocatalytic water reduction activity

Significantly Enhanced Self-Cleaning Capability in Anatase TiO2 for the Bleaching of Organic Dyes and Glazes

Contact Info

Product

Resources

About

Critical Role of the NiO–Ni(OH)₂ Species Loaded Onto TiO₂ Photocatalyst in the Enhancement of H₂ Evolution Activity

Critical Role of the NiO–Ni(OH)₂ Species Loaded Onto TiO₂ Photocatalyst in the Enhancement of H₂ Evolution Activity

Reduced TiO₂ with prolonged electron lifetime for improving photocatalytic water reduction activity