Desalination and Water Treatment
·
2024
·
IF 1
Chaoliang Wang,Xiaoyang Zhao,Yongjun Li,Dehu Yang,Fuyang Liu,Feng Liu,Li Li,Ping Ke
A series of simple and low-cost Ca-doped g-C 3 N 4 (Ca/CN-X) photocatalysts were fabricated through a two-step calcination method for photodegradation of methylene blue (MB) simulated dyeing wastewater. The results showed that the photodegradation efficiency of Ca/CN-15 % on MB removal under visible light was 97.7 %, and the degradation rate constant was 4 times that of CN, showing the best photocatalytic performance. This was attributed to the fact that the doping of Ca expanded the absorption band edge, reduced the band gap, and suppressed the photogenerated electron-hole recombination, thereby increasing its corresponding photocatalytic activity. A possible photodegradation mechanism was explored, and it was found that h + was the main active species during the process. The above indicated that Ca/CN-X can be regarded as a promising catalyst for dyeing wastewater treatment.
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
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Zhi Deng,Jintao Gu,Yuyu Li,Shuai Li,Jian Peng,Xiang Li,Jiahuan Luo,Yangyang Huang,Chun Fang,Qing Li,Jiantao Han,Yunhui Huang,Yusheng Zhao
Na 2 Zn 2 TeO 6 is a potential sodium solid electrolyte of all-solid-state sodium-ion batteries . In this work, Na + ion conductivity and electrochemical performance of layered Ca-doped Na 2 Zn 2- x Ca x TeO 6 ( x = 0–0.05) (NZTO-C x ) electrolytes have been investigated. The highest conductivity has been achieved 7.54 × 10 −4 S cm −1 in NZTO-Cx at x = 0.02, at room temperature due to grain-boundary modification and interlayer-interface elimination. Meanwhile, chemical stability with metallic Na anode and electrochemical window of NZTO-C x are improved by Ca doping. Furthermore, the cycle stability of Na 3 V 2 (PO 4 ) 3 /NZTO-C x /Na solid-state batteries have been successfully increased by Ca doping. These advantages highly demonstrate good potential application prospect of NZTO-C x in all-solid-state sodium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2020
·Vol. 10
·期 17
·5829-5839
·
IF 5.721
Hanlin Chen,Gaoling Wei,Xiaoliang Liang,Peng Liu,Yunfei Xi,Jianxi Zhu
Thermal catalytic oxidation is regarded as an effective technique to eliminate volatile organic compounds (VOCs), whereby perovskite-type oxides have been reported as low-cost and highly efficient transition metal catalysts. In this study, we employ two facile modification methods, i.e., Ca substitution and citric acid etching, to further improve the catalytic activity of LaCoO3 perovskite for toluene oxidation. The Ca-substituted LaCoO3 (La0.9Ca0.1CoO3) and citric acid-etched LaCoO3 (LaCoO3–CA) show T90 values at 220 and 215 °C, respectively, which are substantially lower than that of pristine LaCoO3 (305 °C). When LaCoO3 is modified by both Ca substitution and citric acid etching, i.e., La0.9Ca0.1CoO3–CA, the T90 further decreases to 202 °C, even lower than that of the commercial catalyst 0.5 wt% Pt/Al2O3 (208 °C). In terms of specific reaction rate at 200 °C, the activity of the above catalysts is also enhanced as follows: LaCoO3 (0.14 μmol s−1 m−2) < La0.9Ca0.1CoO3 (0.31 μmol s−1 m−2) < LaCoO3–CA (0.47 μmol s−1 m−2) < La0.9Ca0.1CoO3–CA (0.63 μmol s−1 m−2). The effects of Ca substitution and citric acid etching are discussed in light of the crystal structure, morphology, and lattice defects. On the one hand, Ca substitution and citric acid etching increase the specific surface area and pore volume, which facilitate the contact between toluene and active sites. On the other hand, these methods produce more oxygen vacancies, enhance the reducibility, and facilitate the adsorption of oxygen. The above merits result in the increase in the specific reaction rate. The modified catalysts show a better water resistance than pristine LaCoO3. As verified in the H2O-TPD characterization, this phenomenon is ascribed to the generation of surface hydroxyl groups, which are beneficial for toluene oxidation at high humidity.
研究领域:
环境科学
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2024
·Vol. 31
·期 14
·21267-21278
·
IF 0
Zhao Dongling,Geng Linlin,Jia Yanfei,Wei Jianwen,Zhou Xiaobin,Liao Lei
High-temperature solid adsorbent Li 4 SiO 4 has received broad attention due to its high theoretical adsorption capacity, high regeneration capacity, and wide range of raw materials for preparation. In this paper, a Li 4 SiO 4 adsorbent was prepared by MCM-48 as the silica precursor and modified by doping with metal ions (Ca 2+ and Na + ) for high-temperature capture of low-concentration CO 2 . The results showed that the surface of the Ca-doped (or Na-doped) Li 4 SiO 4 adsorbent developed some particles that are primarily composed by Li 2 CaSiO 4 (or Li 3 NaSiO 4 ). Furthermore, the grains of the adsorbents became finer, effectively increasing the specific surface area and enhancing adsorption performance. Under 15 vol% CO 2 , the maximum CO 2 adsorption was 25.63 wt% and 32.86 wt% when the Ca 2+ doping amount was 0.06 and the Na + doping amount was 0.12, respectively. These values were both higher than the adsorption capacity before the metal ion doping. After 10 adsorption/desorption cycles, the adsorption capacity of Na-doped Li 4 SiO 4 increased by 9.68 wt%, while that of Ca-doped Li 4 SiO 4 decreased by 7.98 wt%. This difference could be attributed to the easy sintering of the Ca-containing adsorbent. Furthermore, a biexponential model was used to fit the CO 2 adsorption curve of the adsorbent in order to study the adsorption kinetics. Compared to the conventional Li 4 SiO 4 , the Ca/Na-doped adsorbent offers several advantages, such as a high CO 2 adsorption capacity and stable cycling ability.
研究领域:
材料科学
·
环境工程
·
化学工程
·
吸附技术
✓ 已验证
DOI
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Xiaolan Chen,Tian Wang,Wanzheng Lu,Tianxiang Cao,Mingzhe Xue,Bing Li,Cunman Zhang
A modified solution method was applied to synthesize cubic garnet solid-state electrolyte Li 7 La 3 Zr 2 O 12 (LLZO) and Li 6.45 Ca 0.05 La 2.95 Ta 0.6 Zr 1.4 O 12 (LCLTZO). The synergetic doping of Ca and Ta is found to induce the formation of cubic LCLZTO with high ionic conductivity of 4.03 × 10 −4 S cm −1 while LLZO without substitution exhibits tetragonal phase with low conductivity. A Li-S cell with sulfur cathode and as-prepared LCLTZO solid electrolyte “separator” was conducted to deliver large initial discharge capacity of 1090 mAh g −1 with high initial Coulombic efficiency up to 92%. Cell with LCLTZO also exhibited better cycling performance at 0.2 C and extremely high Coulombic efficiency (close to 100%) than the cell without solid electrolyte. Better rate performance was also achieved at lower rate (0.2 C, 0.5 C and 1 C) by cell with LCLTZO although it lost advantages at higher rate of 2 C and 5 C due to the limitation of ionic conductivity of LCLTZO. Energy dispersive X-ray spectroscopy (EDS) provided direct evidence that LCLTZO solid electrolyte greatly suppressed the shuttle effect generated by polysulfides . The electrochemical impedance spectroscopy was applied to discuss the difference between cells with and without LCLTZO during the discharge process. Charge transfer reaction referred to soluble polysulfides was found to be slower in cell with LCLTZO than that in cell without solid electrolyte.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 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）