SOLID STATE SCIENCES
·
2018
·
IF 1.861
Jianyi Liu,Yan Liu,Dianxin Jin,Minjia Meng,Yinhua Jiang,Liang Ni,Zhanchao Liu
Tannic-acid-templated large pore mesoporous silica nanoparticle (LMSN) was synthesized using one-pot procedure and the external surface was further modified with APTES (LMSN-N) to immobilize trypsin. After modification, trypsin was difficult to be immobilized on the outer surface of the LMSN due to the electrostatic repulsion. Naturally, study of the trypsin immobilized in the interior pores could be implemented solely. Meanwhile, the activity of immobilized trypsin was optimized by response surface method (RSM), and the ANOVA was employed to explore the interaction between independent variables. The maximum enzyme activity (12.28 U/mg) was obtained under a certain condition that the quality of T-LMSN-N-272 was 153 μg, the pH was 7.9, and the temperature was 40.4 °C. Simultaneously, the immobilized enzyme was proved to possess better thermal stability, storage stability and recycling performance than free enzyme.
研究领域:
生物化学
·
材料科学
·
酶工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS TODAY
·
2018
·
IF 4.667
Dawang Chu,Chen Zhao
The effective and selective conversion of cellulose to valuable fuels and chemicals is highly attractive. In this paper, we prepared a catalyst with the adjacent surface Cu° and oxygen-deficient WO x (2 < x < 3) species by reduction of CuWO 4 precursor, and such catalyst coupled with Ni/activated carbon (AC) attained high yield (71 wt%) and good cycling performances in catalyzing one-step hydrothermal conversion of cellulose to ethylene glycol (EG), highly superior to the performances on physically mixed Ni/C, Cu/C and WO 3 . The increased Cu doping amounts led to a higher ratio of the lower valence state W (V or IV) to the high valence W(VI) as indicated by XPS, XRD, and TPR-H 2 analyses. The oxygen vacancies on the hydrogen-reduced CuWO 4 sample dramatically increased, probably due to the benefits from the substantial dissociated H• on the neighboring Cu° center. The EG yields from cellulose are shown to be proportional to the concentrations of oxygen vacancies on WO x , which catalyzes the important elementary retro-aldol step reaction via adsorbing C 6 sugar intermediates in a specific way. It is inferred that Cu introduction is mainly used to create more oxygen vacancies on the WO x surface that helps adsorbing oxygenates, while Ni fast hydrogenates of hydroxyacetaldehyde to EG and avoids coking, constructing a multi-functional synergistic catalytic process from converting of cellulose to EG in the high-temperature water
研究领域:
催化化学
·
生物质转化
·
绿色化学
·
材料化学
·
能源化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2018
·
IF 5.667
Xiaoyun Lin,Zhenmao Zhu,Chengfei Zhao,Shaoguang Li,Qicai Liu,Ailin Liu,Liqing Lin,Xinhua Lin
In this study, we developed a simple, sensitive and label-free colorimetric sensor for trypsin and its inhibitor using oxidase mimicking activity of protamine-stabilized platinum nanoparticles units (Pro-PtNPs units). Protamine is designed to stabilize PtNPs and served as the substrate of trypsin hydrolysis. The results show that protamine combines several PtNPs together to form active units, which have stronger oxidase mimicking activity than other PtNPs. In addition, the Michaelis constant of the Pro-PtNPs units is smaller than negatively charged citrate capped PtNPs, suggesting that the positively charged Pro-PtNPs units have better affinity with 3,3′,5,5′-tetramethylbenzidine (TMB), which is inconsistent with previous reports. The protamine stabilizer could be hydrolyzed in the presence of trypsin, and the Pro-PtNPs units would be decomposed and aggregated, resulting in a decrease of catalytic activity of Pro-PtNPs units. The color of the solution would be reduced according to the decrease of catalytic activity, so the catalytic activity is linearly related to UV absorbance. The linear range of trypsin detected by this new method is 0.06 μg/mL˜0.6 μg/mL, and the detection limit down to 0.03 μg/mL. Pro-PtNPs units have been successfully applied to the determination of serum trypsin and screening of inhibitors.
研究领域:
生物化学
·
纳米医学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL GEOCHEMISTRY AND HEALTH
·
2019
·Vol. 41
·期 3
·1545-1557
·
IF 3.252
Ye Bin,Cang Yan,Li Ji,Zhang Xiaolei
Chlorine dioxide (ClO 2 ) has been widely used in the process of preoxidation and disinfection as an excellent water treatment reagent. However, the inorganic by-products produced by ClO 2 , such as chlorite (ClO 2 − ) and chlorate (ClO 3 − ) are harmful to human health, and this has become a potential problem when using ClO 2 in drinking water treatment. In this study, ClO 2 alone and a ClO 2 /NaClO combination process were carried out to evaluate the algae removal efficiency of the treatment and the formation of disinfection by-products (DBPs: chlorite, chlorate, trihalomethanes and haloacetic acids) for high algae-laden water with 124.16 µg L −1 chlorophyll a (Chl.a) content. The results show that disinfection with 1.5 mg L −1 ClO 2 alone results in a ClO 2 − concentration exceeding 0.7 mg L −1 . ClO 2 preoxidation/ClO 2 disinfection is applicable for the control of effluent quality, but the ClO 2 − concentration still has an excessive risk when using 0.8 mg L −1 and 0.6 mg L −1 ClO 2 for the two process, respectively. In the ClO 2 /NaClO combination process, the ClO 2 − concentration is below 0.6 mg L −1 , and trihalomethane (THM) and haloacetic acid (HAA) concentrations are lower than 60% of the maximum contaminant levels (MCLs) set by the World Health Organization (WHO). Further, the formation of ClO 2 − is more effectively controlled by NaClO preoxidation/ClO 2 disinfection than ClO 2 preoxidation/NaClO disinfection.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IONICS
·
2019
·Vol. 26
·期 1
·263-272
·
IF 2.289
Luo X. Y.,Meng B.,Xia Z. D.,Chen Q. B.,Dong D. Z.,Zhao M. Y.
In order to investigate the effects of Na 2 CO 3 /ZnO co-addition on the sinterability and electrical conductivity of BaZr 0.1 Ce 0.7 Y 0.1 Sc 0.1 O 3-δ (BZCYSc) ceramic, Na 2 CO 3 and ZnO were added and BZCYSc/ZnO/Na 2 CO 3 ceramic was prepared by mechanical ball milling and high-temperature sintering in air. The crystalline structure, micro-morphology, chemical composition, density, and electrical conductivity of the sintered ceramics were characterized by XRD, SEM, EDS, Archimedes method, and electrochemical impedance spectrum, respectively. The grains size of BZCYSc-2%ZnO-5%Na 2 CO 3 is about 2.5~5 μm. Na 2 CO 3 /ZnO co-addition is beneficial to improve the sinterability and electrical conductivity of BZCYSc. The sintering temperature of BZCYSc can be lowered from 1550 to 1350 °C when 2 mol%ZnO is added. At 550 °C, the electrical conductivities of BZCYSc-2%ZnO-10%Na 2 CO 3 and BZCYSc are 1.90 × 10 −3 S/cm and 1.81 × 10 −3 S/cm. The activation energies of BZCYSc and BZCYSc-2%ZnO-10%Na 2 CO 3 are 0.7529 eV and 0.5641 eV, respectively.
研究领域:
材料科学
·
无机非金属材料
·
固态离子学
·
能源材料
·
陶瓷工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2021
·
IF 8.067
Fengnian Zhang,Fuhao Cheng,Chufei Cheng,Meng Guo,Yufeng Liu,Yang Miao,Feng Gao,Xiaomin Wang
Abatract A series of compositionally complex fluorite oxides (CCFOs) were prepared by ball milling the mixture of ZrO 2 , HfO 2 , Y 2 O 3 , La 2 O 3 , and Pr 6 O 11 followed by conventional solid-state sintering. Both XRD and TG-DSC results demonstrated that single-phase (Zr 0.2 Hf 0.2 Pr 0.2 Y 0.2 La 0.2 )O 2-δ was formed at 1400 °C. Elements in bulk ceramic were uniformly distributed without evident accumulation according to SEM-EDS pictures. TEM results revealed that polycrystalline ceramic powder was assignable to cubic Fm-3m fluorite structure. The electrical conductivity ( σ ) was measured via EIS technology and activation energy ( E a ) of CCFOs was calculated in Arrhenius plots. In the temperature range of 300-750 °C, CCFOs preserved the same conduction mechanism and (Zr 0.1667 Hf 0.1667 Pr 0.1667 Y 0.25 La 0.25 )O 2-δ possessed higher σ and lower E a than other high entropy fluorite oxides which is related to the incorporation of Pr element or the connection of cation-V o complex.
研究领域:
材料科学
·
无机非金属材料
·
固体离子学
·
功能陶瓷
·
能源材料
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2015
·
IF 2.489
Jingzhong Zhao,Weiqiang Xing,Yang Li,Kathy Lu
Oxygen-deficient anatase TiO 2 sheets with dominant (001) facets are becoming a hot research topic due to their promising high activity in heterogeneous reactions . In this work, a series of (001) facets dominated TiO 2 with distributed oxygen vacancies and Ti 3+ was prepared by a simple hydrothermal method with the TiB 2 as a precursor. The as-prepared powders were characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV–visible diffuse reflectance spectroscopy (UV–vis). The results show that the particle size of as-prepared TiO 2 increases and its band gap narrows with the hydrothermal temperature increasing from 140 °C to 180 °C. Besides, oxygen vacancies and Ti 3+ are generated during the TiB 2 hydrolysis, which leads to new absorption spectrum in the visible light region. Photocatalytic test shows that sample prepared at 180 °C presents the highest degradation efficiency.
研究领域:
材料科学
·
光催化
·
纳米材料
·
表面化学
·
半导体材料
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2021
·Vol. 65
·期 5
·1285-1293
·
IF 8.273
Zheng Mang,Li Qi,Liu Mingyang,Liu Jianan,Zhao Chen,Xiao Xudong,Wang Hongli,Zhou Jing,Zhang Liping,Jiang Baojiang
As an n-type semiconductor, In 2 O 3 is considered a promising photocatalyst for producing amino acids using biomass derivatives as precursors. However, similar to other intrinsic semiconductors, In 2 O 3 suffers from poor charge dynamics. Herein, we show the synthesis of Mo-doped In 2 O 3 (Mo-In 2 O 3 ) with a porous rod-shaped structure through a one-step solvothermal reaction followed by calcination. Under visible-light irradiation, Mo-In 2 O 3 achieves a high conversion rate of 81% for the reaction that transforms lactic acid into alanine with a selectivity of 91%. Spectroscopic techniques and density functional theory calculations reveal that Mo doping introduces defect states slightly below the conduction band of In 2 O 3 , which improves the separation of photogenerated electron-hole pairs. In addition, Mo atoms on the surface form extra adsorption and reaction centers that greatly enhance the reaction rate. This work provides insights into the development of transition metal-doped semiconductor photocatalysts to produce amino acids.
研究领域:
材料科学
·
光催化
·
半导体材料
·
生物基化学品
·
分子催化
·
纳米材料
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 85
·81767-81773
·
IF 3.289
Jiaxun Hu,Shuqing Wu,Qin Cao,Wenda Zhang
A facile approach was developed to synthesize core–shell structured alumina/Cu microspheres by means of activation by silver nanoparticles in situ deposited on the polydopamine-coated alumina microsphere surface. This approach takes advantage of both the sufficient reductive capacity of polydopamine towards silver ions and the high activation of silver nanoparticles towards copper deposition. The chemical compositions of composite microspheres were characterized by energy dispersive X-ray spectroscopy (EDS) and Fourier transform infrared spectroscopy (FTIR). The surface morphologies and crystalline structures of the coated alumina were studied by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD), respectively. The adhesion strength between the copper layer and the substrate was evaluated by ultrasonic exposure and thermal shock test. The results showed that silver nanoparticles effectively catalyzed the copper deposition reaction on the polydopamine-coated surface, which led to a faster and more reliable plating process compared with the process without activation. The compact and continuous copper layer obtained showed strong adhesion on the substrate surface.
研究领域:
材料科学
·
纳米技术
·
表面工程
·
复合材料
·
功能材料
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2019
·
IF 6.97
Mingli Zhang,Hengcong Tao,Yongchao Liu,Chao Yan,Song Hong,Justus Masa,Alex W. Robertson,Shizhen Liu,Jieshan Qiu,Zhenyu Sun
Development of naturally abundant, low cost, and energy-efficient electrocatalysts for the oxygen reduction reaction (ORR) is essential for commercialization of fuel cells. In this work, we report simple ultrasonication assisted synthesis of nitrogen and boron dual-doped graphene oxide (NB/GO) and demonstrate its application as an effective ORR catalyst realizing predominantly 4e– reduction of O2 to OH– in 0.1 M KOH. Enhanced ORR electrocatalysis of the dual B and N codoped GO as opposed to GO singly doped with B or N arises from the synergistic interaction of the boron and nitrogen species. The content and configuration of both N and B dopants can be readily tailored by controlling the ultrasonic conditions, thereby permitting tuning of the ORR activity. Furthermore, the developed NB/GO metal-free catalyst exhibited very promising long-term durability and resistance to methanol poisoning compared to the state-of the art Pt/C catalyst.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF ANALYTICAL CHEMISTRY
·
2015
·Vol. 43
·期 10
·1569-1572
·
IF 0.754
Ming-Yan LUO,Bei LÜ,Guo-Bin SHEN,Fei-Fang ZHANG,Bing-Cheng YANG
Electrodialytic eluent generator, one of the key components of ion chromatography system, was fabricated and evaluated. The data achieved indicated that its performance could be comparable to that of commercial one. The maximal operation pressure was over 20 MPa, the generated KOH concentration was up to 100 mM, and the designed usage lifetime was about 354 day (take 8 h working time per day). This device will be helpful to the improvement of domestic instruments of ion chromatography.
研究领域:
分析化学
·
仪器科学与技术
·
分离科学
·
离子色谱技术
✓ 已验证
DOI
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2016
·Vol. 17
·期 2
·536-542
·
IF 2.206
Zhang Jinyang,Li Chuxian,Wang Dingyong,Zhang Cheng,Liang Li,Zhou Xiong
Purpose The environmental safety of both nano-TiO 2 particles and mercury (Hg) pollution has been of widespread concern. Soils and sediments were the main receiving environments of nano-TiO 2 and Hg. There was a strong association between nano-TiO 2 with Hg compounds. Very limited research has been carried out on the impact of nano-TiO 2 on the environmental behavior of Hg in sediments. The objective of this study was to investigate the effects of nano-TiO 2 on the release and transformation of Hg in sediments. Materials and methods Two types of TiO 2 nanoparticles were employed. Sediment samples were collected in the water level fluctuating zone of the Three Gorges Reservoir, China. Sediment samples spiked with HgCl 2 solution were taken as Hg-contaminated sediments. The flooding experiments were conducted using capped borosilicate glass bottles containing 300 ml TiO 2 suspensions (0.2 g L −1 and 0.4 g L −1 ) and 30 g original or Hg-contaminated sediment samples outdoors. All experiments were conducted in triplicate. Water samples were collected at determined interval times over a 60-day period. Sediments were collected on the 60th day. Total Hg (THg) and methylmercury (MHg) in both water and sediment samples and Hg speciation just in sediment samples were determined. A series of control samples without TiO 2 addition were also prepared. Results and discussion The results showed that nano-TiO 2 particles at high content (4 g kg −1 ) promoted the release of Hg in sediments, and the anatase particles showed a stronger effect. Methyl Hg concentrations in waters of nano-TiO 2 treatments significantly decreased by the 10th day. The effect of nano-TiO 2 greatly depended on anatase and rutile particles. After that, methyl Hg concentrations had no significant difference between nano-TiO 2 treatments and the control, except 2 g kg −1 rutile treatment by the 20th day. The changes of Hg speciation in sediments demonstrated that nano-TiO 2 inhibited the transformation of Hg-bound organic matter into the oxidated state, especially upon 2 g kg −1 rutile treatment. This was consistent with the lower MHg concentrations in the 2 g kg −1 rutile treatment. Conclusions Both anatase and rutile nano-TiO 2 were found to affect the release of Hg in sediment. Nano-TiO 2 promoted THg release in sediments and posed an increased risk of Hg contamination in waters, especially for anatase particles. Moreover, nano-TiO 2 inhibited the methylation process of Hg in sediments at the initial stage of flooding and could affect the transformation of Hg speciation in sediments, especially for low-content rutile particles.
研究领域:
环境科学
·
地球化学
·
水体生态学
·
污染控制
·
环境毒理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）