Journal of the American Chemical Society
·
2019
·
IF 14.695
Shiqun Wu,Xianjun Tan,Juying Lei,Haijun Chen,Lingzhi Wang,Jinlong Zhang
Photodriven nonoxidative coupling of CH4 (NOCM) is a potential alternative approach to clean hydrogen and hydrocarbon production. Herein, a Mott–Schottky photocatalyst for NOCM is fabricated by loading Pt nanoclusters on a Ga-doped hierarchical porous TiO2–SiO2 microarray with an anatase framework, which exhibits a CH4 conversion rate of 3.48 μmol g–1 h–1 with 90% selectivity toward C2H6. This activity is 13 times higher than those from microarrays without Pt and Ga. Moreover, a continuous H2 production (36 μmol g–1) with a high CH4 conversion rate of ∼28% can be achieved through a longtime irradiation (32 h). The influence of Ga on the chemical state of a surface oxygen vacancy (Vo) and deposited Pt is investigated through a combination of experimental analysis and first-principles density functional theory calculations. Ga substitutes for the five-coordinated Ti next to Vo, which tends to stabilize the single-electron trapped Vo and reduce the electron transfer from Vo to the adsorbed Pt, resulting in the formation of a higher amount of cationic Pt. The cationic Pt and electron-enriched metallic Pt form a cationic–anionic active pair, which is more efficient for the dissociation of C–H bonds. However, the presence of too much cationic Pt results in more C2+ product with a decrease in the CH4 conversion rate due to the reduced charge-carrier separation efficiency. This study provides deep insight into the effect of the doping/loading strategy on the photocatalytic NOCM reaction and is expected to shed substantial light on future structural design and modulation.
研究领域:
材料科学
·
催化化学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2021
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IF 9.127
Suwei Mou,Kai Huang,Min Guan,Xiang Ma,Jun song Chen,Yong Xiang,Xiaokun Zhang
LiCoO 2 is the dominantly used cathode material in lithium-ion batteries. However, its high-rate capacity and cyclability are limited, especially under high charging voltages, mainly due to the high Li + diffusion barrier . To solve it, we purpose a doping scheme based on two foreign elements: one is with tremendously large ionic radius and weak electronegativity , and the other one has an ionic radius slightly larger than Co, an electronegativity a little weaker than Co, and a high binding energy with O. Ba and Ga are chosen according to this criterion, and their doping effects are compared with that of La and Al. Briefly, Ba is superior to La in weakening the attraction of O 2- to Li + because of its weaker electronegativity and larger ionic radius. Meanwhile, Ga is more capable of enhancing the structural stability at high voltages than Al mainly due to its higher binding energy with O. LiCo 0.998 Ba 0.001 Ga 0.001 O 2 increases Li + diffusivity from 0.77 × 10 -14 to 1.06 × 10 –13 cm 2 ∙s -1 , resulting in a significantly enhanced rate capacity of 114.3 mAh g -1 at 10 C, much better than pristine counterpart (1.6 mAh∙g -1 ). Additionally, it exhibits a particularly high capacity of 199.3 mAh g -1 , and 85% capacity retention over 100 cycles at 0.5 C in 3.0–4.5 V.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA B-CONDENSED MATTER
·
2022
·
IF 2.988
Wei Zhang,Xinhui Yang,Zhiwei Qu,Zirui Liu,Youjin Zheng,Xiangmin Zhao,Xue Wang
Ga-doped ZnO (GZO) powders were synthesized by chemical coprecipitation . GZO powders were annealed in O 2 , Ar, N 2 , and H 2 atmosphere, and the effects of annealing atmosphere on their structure, optical and electrical properties were systematically studied. The results show that the optical and electrical properties of GZO powder were highly influenced by annealing atmosphere. GZO annealed in Ar, N 2 , H 2 atmosphere have excellent electrical resistivity, while GZO annealed in O 2 atmosphere has poor electrical resistivity. According to the annealing contrasted of GZO in different atmosphere, the lower resistivity of GZO is, the lower reflectivity will be. The blue shift of ultraviolet emission (385 nm) in photoluminescence of GZO is related to oxygen vacancy (V O ) and doped Ga, the blue and green emissions (around 500 nm) are originated from V O defects. The density of V O defects and the effective doping rate of Ga will be enhanced when GZO annealed in Ar, N 2 , H 2 atmosphere.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2022
·Vol. 106
·期 1
·158-172
·
IF 2.606
Luo Qiuzi,Sun Yihua,Guo Jin,Zhang Jiangyu,Fang Liang
In this study, the effect of Ti doping ratio on Ti/Ga co-doped ZnO (TGZ) nanopowders was investigated. TGZ nanoparticles with different Ti loadings were prepared using the sol-gel method and analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), infrared spectroscopy (FT-IR), ultraviolet-visible spectrophotometer (UV-Vis), X-ray photoelectron spectroscopy (XPS) and photoluminescence (PL). The results show that when the Ti doping content is low (0.25at%–1at%), all TGZ samples are single-phase and have the same wurtzite structure as pure ZnO, and when the Ti doping content is high (1.5at%–6at%), a second phase appears, which is the Zn 2 TiO 4 inverse spinel phase. When the doping is low, Ti and Ga can replace the position of Zn, the particle size of ZnO is reduced, the absorption of visible light is enhanced, and the catalytic degradation ability is improved. When the powder is highly doped, the shape distortion of the powder is obvious, and the crystal changes from single-phase to multi-phase, but the absorption of visible light is enhanced, and the recombination of electron-hole pairs is reduced. Through the MB degradation experiment, it was found that T 1.5 G 1.5 Z had the strongest degradation ability, and the degradation rate reached 96% in 150 min. With the further doping of Ti, the degradation rate remained at a high level.
Graphical abstract
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2024
·
IF 3.4
Zihao Song,Longjin Huang,Sheng Cui
In this work, a novel strategy for preparing Ga-doped TiO 2 composite aerogel antibacterial agent through the sol–gel method and supercritical technology is demonstrated. The specific surface area of the samples is as high as 175 m 2 g −1 and exhibits a 3D network structure with a multistage pore distribution. The obtained antibacterial agent combines the phototoxicity of TiO 2 , photo-independent toxicity of Ga 3+ , and structural properties of aerogels, showing a synergistic antibacterial effect. On the one hand, TiO 2 produces reactive oxygen species in the presence of light, thus destroying the structure of bacteria. On the other hand, Ga 3+ competitively replaces Fe 3+ and hinders the metabolic process of bacteria. Moreover, the structural properties of aerogels promote superior antimicrobial performance of antibacterial agents. Their antibacterial properties against Escherichia coli and Staphylococcus aureus bacteria are mainly investigated through the inhibition zone and natural colony counting method. In the results, it is shown that the structure and bactericidal activity of TiO 2 aerogel is effectively optimized with Ga 3+ doping. The maximum zone of inhibition of the composite aerogel against E. coli and S. aureus is 17.5 and 16 mm, and the bactericidal rate is as high as 98.57% and 96.60%, which exhibit outstanding bactericidal performance.
研究领域:
材料科学
·
微生物学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Tingzhan Wang,Jingkun Chen,Jiaxuan Chen,Xuan Yao,Gang Chen,Zheng Jiao,Jing-Tai Zhao,Shuai Cheng,Xue-Chun Yang,Qianli Li
N-butanol gas is a common volatile organic compound (VOC) that can pose a threat to human health and pollute the atmospheric environment. However, the n-butanol gas sensors suffer from low response and selectivity. Herein, we synthesized the Ga-doped ZnO (ZOG) sensors by one-step hydrothermal treatment and subsequent calcination. The oxygen vacancies content of 1-ZOG has increased by 46 % compared to pure ZnO. Rich oxygen vacancies can increase the response signal of 1-ZOG to 174.78 in darkness for 100 ppm n-butanol, which is 2.4 times that of ZnO. Furthermore, the gas sensing performance of 1-ZOG is improved by light excitation. Under UV irradiation, the response of 1-ZOG sensor to 100 ppm n-butanol is 3.6 times that of pure ZnO, up to 636.81. Meanwhile, the response signal of 1-ZOG to n-butanol is at least 6.32 times that of other gases under UV light, showing ultra-high selectivity. This study proved that both Ga doped and photo-excited are effective strategies for improving the sensitivity and selectivity of ZnO based gas sensors.
研究领域:
材料科学
·
环境科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
Zhenghang Tian,Yuanyi Liu,Zhiyuan Chen,Zhi Wan,Jizhou Yang,Peilin Zuo,Mingxin Ren,Peng Hu,Feng Teng,Haibo Fan
NiFe layered double hydroxides (NiFe-LDH), as a promising non-precious metal Oxygen Evolution Reaction(OER) catalyst, suffers from the inherent limitations of poor conductivity and insufficient exposure of active sites, coupled with the phenomenon of activity decline at its high current densities, which severely restricts its application in OER. Here, we propose a structurally defective strategy to prepare a self-assembled ultrathin nanosheet structure by introducing Ga3+ ion, and in situ growth of NiFeGa-LDH@NF on nickel foam (NF) to improve its OER performance, and the incorporation of Ga3+ reduces the average thickness of the nanosheets from 4-5 nm to 1-2 nm, which significantly increases the catalyst activity surface area, and further optimized its electronic structure causing the charge transfer resistance a significant decrease. The optimized NiFeGa-LDH@NF provides a high current density of 100 mA cm-2 at an overpotential of 252 mV, which is 43 mV lower than that of the pure NiFe-LDH@NF. Moreover, the voltage changes by only 1.3% after 72 h at a constant current density of 50 mA cm-2, showing its excellent stability. This work presents a new perspective to increase its structural defects by the introduction of transition metal ions and demonstrates the effect on OER performance, providing a new line of thought for the development of higher performance OER electrocatalysts.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Hui Liu,Zongbao Zhang,Xiang Zhang,Yangyang Cai,Yang Zhou,Qiqi Qin,Xubing Lu,Xingsen Gao,Lingling Shui,Sujuan Wu,Jun-Ming Liu
Planar perovskite solar cells (PSCs) based on low-temperature processed gallium (Ga)-doped TiO 2 (Ga-TiO 2 ) films and CH 3 NH 3 PbI 3-x Cl x active layer have been fabricated by one-step method. The annealing temperature of Ga-TiO 2 electron-transport layer (ETL) is only 200 °C. The effect of Ga doping concentrations on the electric properties of Ga-TiO 2 ETL and PSCs has been systematically investigated. At the optimum Ga concentration, the PSCs based on Ga-TiO 2 and TiO 2 ETL achieve the champion power conversion efficiency (PCE) of 17.09% and 14.63%, and an average PCE of 16.51% and 14.15%, respectively. The higher PCE of PSCs based on Ga-TiO 2 ETL (Ga-PSCs) can be attributed to the reduced trap state density, enhanced conductivity, increased electron mobility and suppressed charge recombination, which will lead to higher V oc , J sc and FF, thus the improved PCE. Moreover, the Ga-PSC shows negligible hysteresis and improved stability compared to the reference TiO 2 -PSC. After being stored in air for 28 days, the PCE of unsealed Ga-PSCs can remain to be 86% of its initial value. This work provides an excellent strategy to fabricate efficient and stable PSCs by low-temperature process.
研究领域:
材料科学
·
光伏技术
·
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）