JOURNAL OF CATALYSIS
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2024
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IF 6.5
Jinni Shen,Yuhua Zhong,Jianhan Lin,Haifeng Li,Chengwei Qiu,Xu Liu,Xun Wang,Rong Hu,Jinlin Long,Xuxu Wang,Zizhong Zhang
Photocatalytic water splitting on metal oxides often faces oxygen evolution inefficiency, reflecting the complex interplay of its two half-reactions. Strategies like heterojunctions, cocatalyst loading, or noble metal nanoparticles addition have been explored to address this. Using γ-Ga 2 O 3 nanosheets as a model, we uncovered the formation of −O-O- species as the key barrier to stoichiometric splitting. To tackle this, a strategy was devised, Sr-doping to inhibit surface peroxidation. The resultant Sr-doped γ-Ga 2 O 3 (Sr-Ga 2 O 3 ) significantly improved activity and stability, achieving balanced H 2 and O 2 production under 125 W mercury lamp light. Upon further enhancement with Rh/Cr 2 O 3 cocatalyst via photoreduction, the Sr-Ga 2 O 3 /(Rh/Cr 2 O 3 ) composite demonstrated a remarkable 8.7 mmol·g −1 ·h −1 H 2 and 4.4 mmol·g −1 ·h −1 O 2 evolution rate, 8.3 times higher than γ-Ga 2 O 3 alone, with a 34.1 % quantum efficiency under 260 nm light. This represents a record performance for Ga 2 O 3 -based photocatalytic water splitting. Mechanistically, Sr doping alters surface chemistry to favor direct oxygen release. Our study elucidates molecular-level insights into non-stoichiometric splitting mechanisms and offers a potent strategy to boost metal oxide photocatalysts’ water-splitting efficiency.
研究领域:
材料科学
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环境科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Jinni Shen,Xu Liu,Yuhua Zhong,Chengwei Qiu,Huihui Xu,Hongsheng He,Haifeng Li,Jianhan Lin,Zizhong Zhang,Xuxu Wang
Solar light-driven overall water splitting for hydrogen production is an ideal solution to climate warming and energy shortage issues. Obtaining a highly efficient and stable photocatalyst remains a major challenge at present. Herein, NixP/γ-Ga2O3 nanosheets, which were synthesized from NiCl2, NaH2PO2, and home-made γ-Ga2O3 nanosheets by the photodeposition method under 254 UV irradiation for 30 min, are found as a highly active and durable photocatalyst for pure water splitting into H2 and O2 without a sacrificial reagent. The H2 production rate is as high as 5.5 mmol·g–1·h–1 under 125 W high-pressure mercury lamp irradiation, which is 3.4 and 2.5 times higher than that on the pristine γ-Ga2O3 nanosheets and Pt/γ-Ga2O3 nanosheets, respectively, and is 2.0 times higher than that on the 0.5 wt % Ni2P/γ-Ga2O3 reported previously. However, the O2 evolution rate is much less than the H2 evolution rate in the initial reaction stage. On prolonging the irradiation time, H2 evolution declines, while O2 evolution increases until it reaches its stoichiometric value corresponding to H2. The reason for the photocatalytic behavior of NixP/γ-Ga2O3 is studied and the corresponding mechanism is suggested. The absent or low oxygen evolution in the initial reaction stage is because the dioxygen generated from water oxidation by the photogenerated holes is wholly or partially captured by the surface oxygen vacancies to form the surface peroxide bonds (−O–O−). Once the oxygen vacancies are eliminated by the photogenerated O2, the overall water splitting reaction would reach the steady state. Thereafter, H2 production decreases from 5.5 to 2.0 mmol·g–1·h–1, but the O2 evolution gradually approaches the corresponding stoichiometric value, especially for the photocatalyst treated with H2O2 for 24 h.
研究领域:
材料科学
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催化
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可再生能源
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光化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Kaizheng Gao,Feihua Liu,Fu Lv,Nuomei Li,Man Liu,Ziheng Ye,Minghan Yu,Rui Yin,Chen Zhang,Yuhui Huang,Weiwei Zhao
The rapid development of advanced electronics, hybrid vehicles, etc. has imposed heightened requirements on the performance of polymer dielectrics. However, the energy density (Ue) of polymer dielectrics significantly decreases due to increased leakage current and dielectric loss under high temperatures and high electric fields. Herein, γ phase Ga2O3 (γ-Ga2O3) nanoplates with wide-bandgap (∼4.7 eV) and moderate dielectric constant (∼10.0) were synthesized and incorporated into a polyimide (PI) matrix. The γ-Ga2O3 nanoplates impede charge injection and transport within the nanocomposites under dual trap mechanisms, namely, deep traps introduced by band alignment at the interface between γ-Ga2O3 and PI and the defective spinel structure of γ-Ga2O3 with lattice defects that function as additional charge carrier traps. Additionally, γ-Ga2O3 nanoplates also serve as electron scattering centers and act as electrical barriers; thus, the leakage current and conduction loss get reduced. Consequently, the nanocomposite with 1 wt % γ-Ga2O3 exhibits a discharge energy density of 4.591 J cm–3 and a breakdown strength (Eb) of 501.49 MV m–1 at 150 °C, which are significantly higher than those of commercial biaxially oriented polypropylene (BOPP) at 25 °C. Moreover, the nanocomposite exhibits remarkable cyclic stability over 120,000 cycles with only 1.2% fluctuation. This work provides a semiconductor filler strategy in the design of polymer nanocomposites for capacitive energy storage at high-temperature and high electric field environments.
研究领域:
材料科学
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介电材料
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高分子纳米复合材料
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能源存储
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电子器件
✓ 已验证
DOI
高影响因子
Energy & Environmental Materials
·
2023
·Vol. 7
·期 2
·e12585
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IF 15
Dongdong Zhang,Qiliang Wei,Haili Huang,Lan Jiang,Jie Teng,Ruizhi Yu,Qing Zhang,Shengxing Liu,Lin Wang,Weiyou Yang
Crystalline γ-Ga 2 O 3 @rGO core–shell nanostructures are synthesized in gram scale, which are accomplished by a facile sonochemical strategy under ambient condition. They are composed of uniform γ-Ga 2 O 3 nanospheres encapsulated by reduced graphene oxide (rGO) nanolayers, and their formation is mainly attributed to the existed opposite zeta potential between the Ga 2 O 3 and rGO. The as-constructed lithium-ion batteries (LIBs) based on as-fabricated γ-Ga 2 O 3 @rGO nanostructures deliver an initial discharge capacity of 1000 mAh g −1 at 100 mA g −1 and reversible capacity of 600 mAh g −1 under 500 mA g −1 after 1000 cycles, respectively, which are remarkably higher than those of pristine γ-Ga 2 O 3 with a much reduced lifetime of 100 cycles and much lower capacity. Ex situ XRD and XPS analyses demonstrate that the reversible LIBs storage is dominant by a conversion reaction and alloying mechanism, where the discharged product of liquid metal Ga exhibits self-healing ability, thus preventing the destroy of electrodes. Additionally, the rGO shell could act robustly as conductive network of the electrode for significantly improved conductivity, endowing the efficient Li storage behaviors. This work might provide some insight on mass production of advanced electrode materials under mild condition for energy storage and conversion applications.
研究领域:
材料科学
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能源存储与转换
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DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·
IF 6.4
Tianqi Zhao,Renagul Abdurahman,Qianting Yang,Ruxiangul Aiwaili,Xue-Bo Yin
Herein, we designed and prepared the persistent luminescence nanoparticles (PLNPs) of γ-Ga2O3:Cr,Ba rationally with Cr ions to achieve the near-infrared (NIR) emission at 700 nm and Ba ions to improve the emission intensity by inducing trap distribution. Energy transfer between γ-Ga2O3 and Cr ions occurs as the emission at 508 nm decreases and that at 700 nm increases along with the increased content of Cr ions. In combination with the trap depth, band gap of the host, and energy levels of Cr ions, an emission mechanism was proposed. Thus, NIR emission (700 nm), high brightness, large Stokes shift (446 nm), and long afterglow time (90 min) were achieved with the optimal γ-Ga2O3:0.0025Cr,0.0012Ba (γGCB) under excitation at 254 nm. The emission intensity of γGCB is temperature-dependent for non-contact ratiometric temperature sensing, and temperature linearity ranging from 300 to 420 K was achieved with an absolute sensitivity of 3.4% K−1. γGCB and γ-G2O3 are white under sunlight but exhibit red and green emissions under single excitation at 254 nm. Thus, Morse and binary codes are adapted to achieve encryption information transfer with the combination of γGCB and γ-G2O3. This work provides ideas for selecting a host, emission center, and trap for PLNPs with desirable properties and thus achieves extensive applications, as validated with ratiometric temperature sensing and encryption information transfer.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 44
·15918-15926
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IF 7.393
Zhigang Gao,Luyue Niu,Feifei Zhang,Sikai Wang,Jing Xiao,Jun Chen,Lian Zhang,Jing Ren,Katsuhisa Tanaka
Manipulating the plasmonic properties of metal nanocrystals (NCs) is key to many modern nanophotonic technologies. Here, the strategy of combining Ag+ ↔ Li+ ion exchange and controlled thermal crystallization is proposed as an effective means to prepare transparent nano-glass composites (nano-GCs) embedded with hybrid Ag–metal and γ-Ga2O3:Ni2+ NCs. Only by this method can a large amount of Ag–metal NCs (1.1 mol%) be implanted and well dispersed in the glass matrix without sacrificing their optical transmission properties. The broadband near-infrared (NIR) emission of Ni2+ is enhanced by 100% in the presence of Ag–metal NCs, which is otherwise impossible by raising the Ni2+ concentration due to the limited solubility and intrinsically weak absorption of Ni2+ in nano-GCs. The mechanisms responsible for the enhanced NIR emissions of Ni2+ are comprehensively discussed in the context of both experimental investigations and theoretical simulations. The present study not only provides a promising robust nano-GC-based gain medium for integrated optics but also offers some insights into the plasmonic metal-enhanced photoluminescence for enriched optical functions.
研究领域:
光学
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材料科学
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纳米技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）