MINERALS ENGINEERING
·
2019
·
IF 3.315
Tao Zhang,Tao Jiang,Zhihong Liu
The N235–TOP–sulfonated kerosene system was applied for the recovery of Ge(IV) from a synthetic sulfuric acid leaching solution of secondary zinc oxide , containing Ge(IV), Zn(II), As(III), Fe(III), Si(IV), and Cd(II). The co-extraction of As(III) with Ge(IV) is a challenging problem in the extraction of Ge(IV) from aqueous solution by N235. However, TOP, as a modifier, suppressed the co-extraction of As(III) significantly. The effects of factors including N235 concentration, extraction time, tartaric acid to Ge(IV) molar ratio and temperature on the extractions of Ge(IV) and As(III) were studied. At an organic/aqueous (O/A) phase ratio of 1/1, aqueous phase pH of 1.2, extraction time of 10.5 min, tartaric acid-to-Ge(IV) molar ratio of 5.0, and temperature of 25 °C, the extraction efficiency of Ge(IV) reached 93.9%, whereas only 1.3% of As(III) was extracted by the 25%(v/v)N235–10%(v/v) TOP–sulfonated kerosene system in a single stage extraction. The Ge(IV) in the raffinate was less than 1.5 mg/L when employing a five-stage continuous countercurrent extraction at an O/A ratio of 1/10. In addition, aqueous NaOH solution of 0.5 mol/L was an appropriate reagent for the stripping of both Ge(IV) and As(III) at an O/A ratio of 1/1 and 25 °C for 10.0 min.
研究领域:
冶金工程
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Tao Jiang,Pengcheng Wang,Tao Zhang,Deqing Zhu,Zhihong Liu
Owning to the lack of commercial independent germanium deposit and the ever-growing germanium demand of high-tech field, the recovery of germanium from various resources shows strategic significance. In this study, a novel solvent extraction system based on primary amine (N1923) and hydroxycitric acid (HCA) was developed to recover germanium from leaching liquors of secondary zinc oxide and some typical resources. The results indicated that the solvent system showed high extraction efficiency and germanium selectivity ; equilibrium pH and the dosage of HCA were the key parameters for germanium recovery, the germanium extraction capacity of an organic phase with 0.24 mol/L N1923 was 7.97 g/L; germanium could be separated from zinc, arsenic, iron, and cadmium at an equilibrium pH of 1.0, and the separation factors of germanium to those elements were up to 1778, 232, 67074, and 14706, respectively; the system was also with well separation performance of germanium from typical germanium containing leachates of copper cake and coal fly ash. Stoichiometry analysis and FT-IR, NMR, and ESI-MS spectra demonstrated that the extraction of germanium followed a coordination anion extraction mechanism, the germanium extraction complexes was RNH 3 ⋅GeO 2 C 6 H 4 O 7 . 0.5 mol/L NaOH can be selected for the stripping of germanium. 2
研究领域:
冶金学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 23
·34607-34621
·
IF 0
He Haixia,Cheng Yanhui,Qiu Siwei,Sun Lei,Jin Bohua,Yuan Xiangjuan
A series of ZnO decorated reduced graphene oxide (rGO) (ZnrGO x ) with different doping ratios were synthesized by the alkaline hydrothermal method using graphene oxide (GO) and Zn(NO 3 ) 2 ·6H 2 O as precursors, and subsequently used for the adsorption study of Cr(VI) in water. The morphology, crystalline phase structure, and surface elemental properties of ZnrGO x composites were revealed by XRD, SEM, BET, FT-IR, and XPS characterizations. The results showed that ZnO nanoparticles can be clearly seen on the surface of layered rGO. Meanwhile, as the doping rate increased, the C = C double bonds were broken and more carboxylic acid groups formed in ZnrGO x . In addition, the ZnrGO 0.1 composite had the most excellent adsorption performance and good stability, and reusability. The adsorption removal rate of Cr(VI) can reach 99%, and the maximum adsorption amount of Cr(VI) was 68.9655 mg/g in 3 h. The isothermal and kinetic model simulations showed that Cr(VI) adsorption on ZnrGO 0.1 composite is a chemical adsorption process, spontaneous and endothermic. Based on the concentrations of different valence states of Cr in the solid and liquid phases, 40% of Cr(VI) was reduced to Cr(III) on the surface of ZnrGO 0.1 composite. Moreover, the adsorption-reduction mechanisms of Cr(VI) on ZnrGO 0.1 composite were further elucidated. The ZnrGO 0.1 composite manifested great potential as an efficient adsorbent for Cr(VI) removal. Graphical Abstract
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
Nanomaterials
·
2024
·Vol. 14
·期 24
·2022
·
IF 4.4
Qiongmei Mai,Yu Lu,Qianyu Cai,Jianglong Hu,Yunyou Lv,Yonglan Yang,Liqiang Wang,Yuezhao Zhou,Jie Liu
Sclerotinia sclerotiorumis one of the fungi that cause plant diseases. It damages plants by secreting large amounts of oxalic acid and cell wall-degrading enzymes. To meet this challenge, we designed a new pH/enzyme dual-responsive nanopesticide Pro@ZnO@Pectin (PZP). This nanopesticide uses zinc oxide (ZnO) as a carrier of prochloraz (Pro) and is encapsulated with pectin. When encountering oxalic acid released bySclerotinia sclerotiorum, the acidic environment promotes the decomposition of ZnO; at the same time, the pectinase produced bySclerotinia sclerotiorumcan also decompose the outer pectin layer of PZP, thereby promoting the effective release of the active ingredient. Experimental data showed that PZP was able to achieve an efficient release rate of 57.25% and 68.46% when pectinase was added or under acidic conditions, respectively. In addition, in vitro tests showed that the antifungal effect of PZP was comparable to that of the commercial Pro (Pro SC) on the market, and its efficacy was 1.40 times and 1.32 times that of the Pro original drug (Pro TC), respectively. Crucially, the application of PZP significantly alleviated the detrimental impacts of Pro on wheat development. Soil wetting experiments have proved that PZP primarily remained in the soil, thereby decreasing its likelihood of contaminating water sources and reducing potential risks to non-target organisms. Moreover, PZP improved the foliar wettability of Pro, lowering the contact angle to 75.06°. Residue analyses indicated that PZP did not elevate prochloraz residue levels in tomato fruits compared to conventional applications, indicating that the nanopesticide formulation does not lead to excessive pesticide buildup. In summary, the nanopesticide PZP shows great promise for effectively managingSclerotinia sclerotiorumwhile minimizing environmental impact.
研究领域:
植物病理学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Xiaozhe Liu,Tiejun Lin,Peigong Liu,Liangshu Zhong
Fischer-Tropsch to olefins (FTO) with controllable iron carbide phase and high carbon utilization efficiency for Fe-based nanocatalyst attracts great interest but remains challenge. Herein, we report that the metastable Fe 7 C 3 phase can be effectively tailored by altering shell thickness of hydrophobic SiO 2 over a core-shell nanostructured FeZn@SiO 2 -c nanocatalyst. χ-Fe 5 C 2 was the dominated iron carbide phase for FeZnO x and FeZn@SiO 2 nanocatalysts, while numerous Fe 7 C 3 phases existed for hydrophobic FeZn@SiO 2 -c nanospheres . Compared with FeZnO x , the CO 2 selectivity of FeZn@ 4.1-SiO 2 -c decreased by > 70%, while 1.7-fold higher olefins selectivity was simultaneously obtained during syngas conversion process. The hydrophobic interface greatly suppressed the water-gas-shift reaction by promoting the quick diffusion of water, and the as-formed H 2 -lean and CO-rich local chemical environment benefits the formation of Fe 7 C 3 and olefins products. This work provides a promising strategy to design phase-stable Fe 7 C 3 with improvement of carbon efficiency for Fe-based nanocatalysts.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2024
·Vol. 14
·期 18
·12954-12965
·
IF 3.9
Thi Viet Ha Luu,Hong Yen Xuan Nguyen,Quoc Thang Nguyen,Quang Bac Nguyen,Thi Ha Chi Nguyen,Ngoc Chuc Pham,Xuan Dung Nguyen,Trung Kien Nguyen,Ngoc Nhiem Dao
This study attempted to improve the photocatalytic activity of zinc oxide (ZnO) semiconductors in the visible light region by introducing the co-doping of carbon (C) and tantalum (Ta) to ZnO (ZTC) using a simple hydrothermal method with the respective precursors. The obtained uniform ZTC nanoparticles with an average crystal size of 29.30 nm (according to Scherrer's equation) revealed a redshift with a decrease in bandgap (Eg) from 3.04 eV to 2.88 eV, allowing the obtained photocatalyst to absorb the energy of the visible light for photocatalysis. Furthermore, the Zn 2p and Ta 4f core level spectra confirmed the presence of Zn2+ and Ta5+ in the ZTC sample. In addition, the infrared spectra identified hydrogen-related defects (HRDs), while the O 1s spectra indicated the existence of oxygen vacancies (VO). Electrochemical tests revealed improvement in the electron conductivity and charge separation of the obtained materials. To follow, the photocatalytic performance assessment was conducted by varying the C/Zn2+ ratios (5, 10, and 15 mol%) in ZTC samples, the initial RhB concentration (7, 15, and 30 ppm), and the pH of the RhB solution (3.0–10.0). The photodegradation on ZTC samples showed the most effectiveness for a 7 ppm RhB solution with a C/Zn2+ ratio of 10 mol% in the slightly alkaline medium (pH 9.0). Additionally, ZTC also exhibited commendable durability after being reused several times. The nature of RhB photodegradation was proposed and discussed via a mechanism at the end of this work.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2019
·
IF 0
Sefiu A. Rasaki,Tiju Thomas,Minghui Yang
Due to high surface area and large pore volume, nanostructure zinc oxides/its composites have gained a lot of research interests for heavy metal removal from water. Low stability of the ZnO at low and high pH is however a problem. In this work, ZnO@MgO, ZnO and MgO are synthesized via co-precipitation, followed by calcinations. The samples show remarkable removal of Pb(II) from water when compared to commercial samples; the best results is obtained using ZnO@MgO which exhibit adsorption capacity of 250 mg g −1 equivalent to 100% removal capacity. The optimum removal capacity is retained in a wide range of pH (i.e. pH 6–9) at temperature 30 °C. Low adsorption capacity coupled with low stability in acidic condition; a problem associated with ZnO-based adsorbents when it is being used for the removal of heavy metals from water/wastewater; often prevents this system from being practically used; is overcome here. The ZnO@MgO adsorbent shows chemical stability over wide range of pH(2–9). The adsorption is chemisorptive in nature, endothermic and evidently aided by high surface heterogeneity (△H° ˜25 kJ mol-1 and △S°˜110.6 J mol −1 K −1 ). Appreciable adsorption capacity over wide range of pH-value, high recovery and reusability results from nanosphere morphology of the composite sample; all these novel properties are attributed to the strong electronic coupling effect between MgO and ZnO. This work is expected to spur further research on ZnO-based composite materials in allied areas, including (i) mitigation of atmospheric pollution and (ii) water treatment processes.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
·
2023
·Vol. 32
·期 23
·10626-10636
·
IF 2.3
Zhao Santuan,Xing Donghua,Zhen Kai,Niu Zhongpei,Li Guangda
The wetting and spreading of glass binders on silver have an important influence on the properties of conductive silver paste. Therefore, it is necessary to consider the wettability between glass binder and silver when designing conductive silver paste. In the present work, the wettability of the Bi 2 O 3 -B 2 O 3 (-ZnO)/silver system was studied in detail. A high temperature contact angle measuring instrument was used to study the dynamic contact angles of different glass/silver systems. After the wetting test, the microstructure of the surface and cross section of the droplet/substrate was studied. In addition to the bulk liquid usually observed, the precursor membrane was observed near the triphase line. The wetting and spreading of glass melt are mainly controlled by the viscosity of glass melt and the blocking effect of the triphase line. In the process of heating up, the wetting process of glass/silver system can be divided into three stages: incubation stage, temporary equilibrium stage, and rapid spreading stage. The content of zinc oxide has a great influence on the wetting behavior of Bi 2 O 3 -B 2 O 3 (-ZnO)/silver systems.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Lu Song,Yafei Wang,Jing Ma,Qinghua Zhang,Zhijian Shen
Zinc oxide (ZnO) is a competitive candidate in semiconductor photocatalysts, only if the efficiency could be fully optimized especially by tailored nanostructures. Here we report a kind of core/shell structured Zn/ZnO nanoparticles with enhanced photocatalysis efficiency, which were synthesized by a highly-productive gaseous laser ablation method. The nanodroplets generated by laser ablation would be reduced to zinc in the protective atmosphere, and further be oxidized at surface to form a specific core/shell structured Zn/ZnO nanoparticles within seconds. Thanks to the formation of this Zn-ZnO Schottky junction, the photocatalysis degradation efficiency of such core/shell Zn/ZnO nanostructure is significantly improved owing to the enhanced visible light absorption and inhibited carrier recombination by introducing the metallic zinc.
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
ChemCatChem
·
2022
·Vol. 14
·期 6
·e202101794
·
IF 5.497
Longfei Zhu,Sen Ye,Jing Wang,Jiazheng Zhu,Guangke He,Xiang Liu
Graphical Hydrogen pool : Recyclable Ir/ZnO-catalysed additive-free transfer hydrogenation of aldehydes and ketones using methanol as hydrogen source was achieved at 110 °C, delivering alcohols in up to 98 % yield. The fine cooperation of ZnO and positively charged IrO x enables the complete cleavage of O−H and less reactive C−H bonds of methanol to generate active H for carbonyl hydrogenation. The use of methanol as abundant and low-toxic hydrogen source under mild and clean conditions is promising for the development of safe and sustainable reduction processes, but remains a daunting challenge. This work presents a recyclable ZnO-supported Ir catalyst for the additive-free transfer hydrogenation of aldehydes and ketones using methanol as hydrogen source at 110 °C, delivering alcohols in up to 98 % yield. Mechanistic studies disclose that methanol is first dehydrogenated to formaldehyde and then fully decomposed into active hydrogen species for hydrogenation. The superior performance is related to the high ratio of positively charged IrO x species and their ultrafine dispersion over ZnO. And the delicate cooperation of IrO x and ZnO enhances the catalytic activities for the selective scission of O−H and less reactive C−H bonds in methanol, maintaining a good balance between methanol decomposition and C=O hydrogenation in this green transfer hydrogenation.
研究领域:
化学催化
·
绿色化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Yizhen Cheng,Jing Kang,Pengwei Yan,Jimin Shen,Zhonglin Chen,Xinwei Zhu,Qiang Tan,Linlu Shen,Shuyu Wang,Shaobin Wang
Herein, a highly dispersed catalyst (ZnO x -500) was synthesized for heterogeneous catalytic ozonation (HCO), which had a simple ZnO crystal phase but riched in oxygen vacancies (OVs). The O 3 /ZnO x -500 system exhibited both superior catalytic activity and stability after several cycles, providing a promising strategy for atrazine (ATZ) removal. The strong inhibition of phosphoric acid validated the dominant role of the hydroxyl group (−OH) from water molecule (H 2 O) dissociation on the zinc site near OVs. Density functional theory calculation further revealed that OVs on (100) and (101) planes could make more zinc sites exposed and facilitate the formation of hydrated −OH, which was easier to approach O 3 for its decomposition to generate hydroxyl radical ( • OH). This work revealed the intrinsic relationship between OVs and hydrated −OH in an aqueous solution, providing new insight into the solid-liquid interface mechanism of HCO.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2024
·
IF 5.7
Yang Leng,Yue Sun,Peixiao Sun,Miaojun Xu,Hongjian Zhang,Xiaoli Li,Bin Li
Thermal management materials are the solution to heat dissipation issues in electronic devices, which are considered vital to the device's reliability and lifetime. Therefore, it was of great significance to develop a new type of epoxy resin composites with flame retardant , thermal conductivity and toxicity reduction. Here, dendritic zinc oxide (D-ZnO) was designed and synthesized after annealing the metal-organic framework (MOF) precursor and then using it to fabricate a thermally conductive epoxy resin (EP) thermoset . The synthesized d -ZnO reached a high specific surface area of 40.389 m 2 g −1 , which is about 14 times higher than that of commercial ZnO (C-ZnO). Remarkably, the EP/D-ZnO thermosets reaches a thermal conductivity (TC) of 1.10 Wm −1 K −1 at a low filler loading of 10 wt%, which is more than 4.5 times more than pure EP. In the meantime, the TC of the d -ZnO composite was 120 % higher than that of the commercial ZnO composite at the same loading. The coefficient of thermal expansion (CTE) of EP/10wt% d -ZnO thermoset decreased by 68.6 ppm K −1 compared to pure EP. The excellent thermal diffusion performance could be attributed to the polarized interfaces of d -ZnO, which forms heat conduction pathways. Thus, with addition of functionalized d -ZnO, the peak CO production and peak CO 2 production were decreased from 0.036 gs −1 and 0.80 gs −1 for pure EP to 0.026 gs −1 and 0.50 gs −1 (EP/D-ZnO thermosets). The EP/D-ZnO thermosets reported by this strategy demonstrate great potential as next generation thermal management materials.
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）