Journal of the American Chemical Society
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2017
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IF 13.858
Fen Liu,Ningdong Feng,Qiang Wang,Jun Xu,Guodong Qi,Chao Wang,Feng Deng
The detailed structure–activity relationship of surface hydroxyl groups (Ti–OH) and adsorbed water (H2O) on the TiO2 surface should be the key to clarifying the photogenerated hole (h+) transfer mechanism for photocatalytic water splitting, which however is still not well understood. Herein, one- and two-dimensional 1H solid-state NMR techniques were employed to identify surface hydroxyl groups and adsorbed water molecules as well as their spatial proximity/interaction in TiO2 photocatalysts. It was found that although the two different types of Ti–OH (bridging hydroxyl (OHB) and terminal hydroxyl (OHT) groups were present on the TiO2 surface, only the former is in close spatial proximity to adsorbed H2O, forming hydrated OHB. In situ 1H and 13C NMR studies of the photocatalytic reaction on TiO2 with different Ti–OH groups and different H2O loadings illustrated that the enhanced activity was closely correlated to the amount of hydrated OHB groups. To gain insight into the role of hydrated OHB groups in the h+ transfer process, in situ ESR experiments were performed on TiO2 with variable H2O loading, which revealed that the hydrated OHB groups offer a channel for the transfer of photogenerated holes in the photocatalytic reaction, and the adsorbed H2O could have a synergistic effect with the neighboring OHB group to facilitate the formation and evolution of active paramagnetic intermediates. On the basis of experimental observations, the detailed photocatalytic mechanism of water splitting on the surface of TiO2 was proposed.
研究领域:
材料科学
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催化化学
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物理化学
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PubMed
高影响因子
Inorganic Chemistry Frontiers
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2017
·Vol. 5
·期 2
·481-489
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IF 4.036
Wanbao Wu,Xu Li,Zhaohui Ruan,Yudong Li,Xianzhu Xu,Yuan Yuan,Kaifeng Lin
A TiO2 trapped meso/macroporous g-C3N4 heterojunction (mm-CNT) photocatalyst is fabricated by hydrolysis and sintering of tetrabutyl titanate on meso/macroporous g-C3N4 prepared via a facile hard template method. TiO2 nanoparticles are highly dispersed and some of them are trapped in the pores of meso/macroporous g-C3N4. The photocatalytic performance of mm-CNT is assessed through degradation of Rhodamine B solution under visible light irradiation, which displays much better photocatalytic performance than that over pristine meso/macroporous g-C3N4 and pristine g-C3N4. Based on the characterization results, it is reasonable to believe that the enhanced photocatalytic activity should be attributed to the unique meso/macroporous architecture and heterojunction structure, which results in improved mass transfer and enhances the separation efficiency of exciton dissociation. Besides, an optical simulation is initially utilized to study the optical absorption characteristics of mm-CNT since the optical absorption ability of a photocatalyst is one of the most important aspects influencing the photocatalytic ability. As a result, the enhanced ability of light absorption observed on the heterojunctions should be also favorable to achieve improved photocatalytic performances. On account of the analysis results, a possible photocatalytic mechanism for enhanced visible light photocatalytic activity is proposed.
研究领域:
材料科学
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光催化
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高影响因子
Sustainable Energy & Fuels
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2023
·Vol. 7
·期 9
·2209-2218
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IF 5.6
Suyan Li,Xiaoyu Hu,Yubo Li,Meiying Wang,Yu Chen,Manman Mu,Lijun Zhang
As a green and sustainable energy technology, converting solar energy into hydrogen peroxide (H2O2) chemical energy has become one of the key research fields of photocatalysis. It has been reported that TiO2 has reached an excellent H2O2 productivity of 3.3 mM h−1, and, therefore, there is value in using it for further research. Herein, a novel method for repairing and improving the surface of TiO2 was developed using small organic molecules that can enter the nanopores of TiO2 to form C, N, and O co-doped graphite-like hybrid structures. Thus, efficiently and conveniently, a multifunctional dihydropyridine with an electron-donating hydroxyl substituent successfully conducted thermally induced intermolecular condensation and subsequent in situ graphitization, resulting in efficient regulation of surficial properties. The results show that hybrid species enhanced the separation and transmission of photogenerated charges, reduced the photocatalytic effect for the decomposition of H2O2, and provided an effective channel for photocatalytic H2O2 synthesis. Under xenon lamp illumination, an initial rate of 10.22 mmol (h g)−1 H2O2 was obtained, which exceeded that for all previously reported catalysts. In addition, ACMD successfully increased the light utilization efficiency of nano-TiO2, with an apparent quantum efficiency (AQE) of 24.5% at 365 ± 5 nm and a solar-to-chemical conversion (SCC) efficiency of 2.18% under irradiation above 300 nm. Its visible light performance was significantly improved to afford 3.12 mmol (h g)−1 H2O2 with an SCC of 1.17% under irradiation greater than 420 nm. Because of the diversity of such organic molecules, this method provides researchers with many opportunities to further optimize hybrid species on the surface of TiO2, and, therefore, it is significant for the development of photocatalysts.
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高影响因子
ACS Biomaterials Science & Engineering
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2022
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IF 5.395
Huakai Chen,Jinglin Zhang,Fengjuan Yang,Tongyao Lin,Jingxian Zhang,Xiang Cai,Peng Zhang,Shaozao Tan
Titanium (Ti) and its alloys are extensively applied in dental and orthopedic implants due to their characteristics of good mechanical property and corrosion resistance. However, Ti and its alloys suffer from the absence of certain biological activity and antibacterial ability. Herein, we synthesized a titanium dioxide (TiO2) nanorod array on the surface of a Ti plate, and the obtained TiO2 nanorod array was further modified by Cu ions through ion implantation technology in an attempt to endow medical Ti with an antibacterial ability and maintain a normal biological function synchronously. The antibacterial ability of the TiO2 nanorod array with the incorporation of Cu ions was vastly improved compared with those of the unmodified TiO2 nanorod array and pure Ti. In particular, owing to the synergy between the chemical damage of the released Cu2+ to the cell and the mechanical cracking of the TiO2 nanorod array, the antibacterial rate of the TiO2 nanorod array modified by Cu ions against Escherichia coli or Staphylococcus aureus could reach 99%. In addition, no cytotoxicity was detected in such prepared coating during the CCK-8 assay. Moreover, the corrosion resistance of the sample was significantly better than that of pure Ti. Overall, we demonstrated that the application of ion implantation technology could open up a promising pathway to design and develop further antibacterial material for the biomedical domain.
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高影响因子
ENERGY & FUELS
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2024
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IF 5.2
Huanjin Jiang,Jie Yang,Shangzhen Feng,Hantao Zhou,Jixiang Chen
Ni3Sn2/TiO2, Ni3Sn2/TiO2–ZrO2(x:y) (x:y indicates the Ti/Zr atomic ratio), and Ni3Sn2/ZrO2 catalysts were prepared by the sol–gel method and tested for in situ hydrodeoxygenation of methyl palmitate with methanol as the hydrogen donor. The Ni3Sn2 intermetallic compound (IMC) is formed in all of the catalysts. The Ti–O–Zr bonds are generated in the TiO2–ZrO2 mixed oxide, leading to more Lewis acid sites on Ni3Sn2/TiO2–ZrO2(x:y) than those on Ni3Sn2/TiO2 and Ni3Sn2/ZrO2, and Lewis acid sites may contribute to the C–O bond cleavage. Especially, among the as-prepared catalysts, Ni3Sn2/TiO2–ZrO2(2:1) has the largest specific surface area and the smallest Ni3Sn2 particles, subsequently giving rise to the highest activity for in situ hydrodeoxygenation. The decarbonylation pathway dominates on all of the supported Ni3Sn2 IMC catalysts. At 330 °C, the yield of n-pentadecane on Ni3Sn2/TiO2–ZrO2(2:1) reaches 91.2%. Ni3Sn2/TiO2–ZrO2(2:1) shows slight deactivation after reaction for five times, mainly due to carbon deposition and the slight sintering of Ni3Sn2 IMC particles.
研究领域:
催化化学
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可再生能源
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材料科学
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高影响因子
MICROCHIMICA ACTA
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2019
·Vol. 186
·期 7
·1-9
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IF 5.479
Qin Xiaofei,Geng Liping,Wang Qianqian,Wang Yan
A photoelectrochemical (PEC) method is described for aptamer-based detection of ofloxacin (OFL). It is making use of a TiO 2 nanotube array (NTA) that is sensitized with a structure composed of polydopamine and silver sulfide nanoparticles. The NTA were prepared by a two-step synthetic method. First, the TiO 2 nanotube electrode was covered with Ag 2 S nanoparticles via successive ionic layer adsorption and reaction strategy. Next, they were coated with a thin film of polydopamine (PDA) by in-situ polymerization. The inorganic/organic nanocomposites exhibit distinctly enhanced visible-light PEC activity. This was exploited to fabricate a PEC aptasensor. The PDA film serves as both the sensitizer for charge separation and as a support to bind the aptamer against OFL. The aptasensor undergoes a decrease in photocurrent due to the formation of the aptamer-OFL complex. Under the optimized conditions and at a typical working potential of 0 V (vs. Hg/Hg 2 Cl 2 ), the NTA has a linear response in the 5.0 pM to 100 nM OFL concentration range and a 0.75 pM detection limit (at S/ N = 3). The aptasensor was successfully applied to the determination of OFL in spiked milk samples.
Schematic illustration for the preparation and mechanism of the photoelectrochemical aptasensor for ofloxacin. TiO 2 NTs: TiO 2 nanotube arrays; PDA: polydopamine; MCH: 6-mercapto-1-hexanol; OFL: ofloxacin; PEC: photoelectrochemistry; CB: conduction band; VB: valence band; LUMO: the lowest unoccupied molecular orbital; HOMO: the highest occupied molecular orbital; AA: ascorbic acid.
研究领域:
分析化学
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生物传感技术
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高影响因子
Journal of Materials Chemistry A
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2017
·Vol. 5
·期 38
·20195-20201
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IF 8.867
Jiuwang Gu,Qitong Huang,Yufei Yuan,Kai-Hang Ye,Zilong Wang,Wenjie Mai
Unfavorable interfacial electron back-injection, sluggish surface kinetics, and poor bulk conductivity leading to remarkable recombination are the key issues which significantly hinder the solar-to-hydrogen efficiency of PEC photoanodes. In this study, Ti foil is employed as the substrate for fabricating BiVO4 photoanodes. Surface passivation of TiO2 is sophisticatedly designed to block interface recombination in solar water splitting for the first time, so that a significant two-fold increase in photocurrent and a large decrease in dark current are observed. In addition, to address the other two issues, CoOx oxygen evolution catalysts (OECs) and Mo/N doping are applied to increase the photocurrent density and applied bias photon-to-current efficiency to 5.04 mA cm−2 at 1.23 VRHE and 1.41% at 0.75 VRHE, respectively, under AM 1.5 G illumination, which suggests the great potential of integrating strategies to target specific issues in BiVO4 photoanodes.
研究领域:
材料科学
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能源科学
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光电化学
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DOI
高影响因子
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