WATER AIR AND SOIL POLLUTION
·
2019
·Vol. 230
·期 4
·1-13
·
IF 1.774
Liu Yong,Wang Gui,Yang Wenning,Yang Jie,Li Jia
Biotemplating method is a promising way to obtain hierarchical materials with unique morphology and property. In the current work, a novel hierarchically porous ZnAl-CLDH (calcined layered double hydroxides)/FeWO 4 had been successfully synthesized by a facile biotemplated method. The obtained samples were characterized in detail via FESEM-EDX, TEM, XRD, IR, TGA, and BET techniques. The as-synthesized ZnAl-CLDH/FeWO 4 hierarchical microspheres were composed of ZnAl-CLDH nanosheets and FeWO 4 nanoparticles. The obtained sample exhibited both high adsorption and visible-light photocatalytic activity toward Congo Red (CR) in water. It was found that the adsorption process was well described by the pseudo-second-order kinetic model and the Langmuir isotherm model, while the photocatalytic degradation process was well fitted to the first-order kinetics model. The enhanced photocatalytic performance was mainly due to the hierarchically porous structure that could offer more exposed active sites, as well as the unique energy band structure of heterostructures, that facilitated the efficient separation and transfer of photoinduced carriers and enhanced light harvesting. In addition, the as-prepared sample had quickly magnetic response and could be easily separated from water under an external magnetic field after wastewater treatment.
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Zhongjuan Wang,Yunhe Li,Guohua Shen,Yuanqing Li,Xinyi Zhang,Jianfeng Gou,Xiuwen Cheng
In recent decades, persulfate activation technology has been used to degrade persistent organic pollutant. Moreover, both transition metal-based catalyst and metal-free catalyst have become more efficient activator. In this study, Cu-Fe LDH was synthesized and calcined at different temperature to form into metal oxides (CLDH). Then, the CMK/LDH and CMK/CLDH composites were fabricated by co-precipitation and sonic treatment, respectively. Furthermore, the prepared samples were used to activate PS for sulfamethoxazole degradation. Based on the several characterizations and degradation experiments, a comparative study of different catalysts was conducted and the results reached the following factors: i CMK/LDH owned the best capacity of PS activation on sulfamethoxazole decomposition, 84.9% SMX of 25 mg/L was degraded with less dosage of persulfate (0.5 g/L) and catalyst (0.15 g/L) being added. ii CMK/CLDH owned the better adaptability of initial pH value compared with CMK/LDH. Meanwhile, based on scavenger quenching experiment and chronoamperometric, it was speculated that non-radical pathway played more role in CMK/LDH composite/PS/SMX system compare with radical pathway. It was interesting to find that SO 4 • − were mainly generated by LDH while HO• were mainly produced by CMK part. However, the non-radical pathway for SMX decomposition was only ascribed to the electron bridge effect that the CMK owned. This study might provide a theoretical support for further studies on comparison about LDH and the metal oxides originating from calcination of LDH for PS activation.
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
Journal of Building Engineering
·
2025
·
IF 7.4
Jielu Zhu,Bingzhi Xiang,Fanghua Liu,Lina Xiao,Yong Zhou,Junwei Song,Haijiao Xie
Functional materials represented by calcined layered double hydroxide (CLDH), nano-silica (SiO 2 ), and microcapsules are frequently incorporated into cement-based composites to accelerate cement hydration or autonomously heal matrix microcracks, thereby enhancing the chloride-binding quantity and inhibition performance of cementitious system. In this work, CLDH and SiO 2 were employed to target modify microcapsules (CLDH/SiO 2 -MC), aiming to achieve the functional coupling effects of three materials. The study revealed that CLDH and SiO 2 were successfully anchored within the microcapsule wall and improved the surface roughness of modified microcapsules. The targeted modification strategy is beneficial to improve the interfacial bonding between microcapsules and cement paste. Interestingly, the alkaline pore solution induced the hydration reaction of active SiO 2 component within the surface of modified microcapsules. Compared with the reference group, cement paste specimens incorporating 3 % and 6 % microcapsule demonstrated 30.76 % and 53.85 % enhancements in chloride binding capacity, respectively. The D RCM values of cement mortar with CLDH/SiO 2 -MC additions of 0 %, 3 %, 6 %, and 9 % were 19.95, 14.63, 17.00, and 19.52 × 10 −12 m 2 /s, respectively. The synergistic corrosion inhibition effects of microcapsules resulted in higher R ct value of steel electrode, and the highest inhibition efficiency of CLDH/SiO 2 -MC was 97.84 %. The density functional theory (DFT) calculations show that the charge exchange capacity between CLDH/SiO 2 and ethyl cellulose is 2.36 e – , with metal atoms serving as electron donors. The CLDH/SiO 2 targeted modified microcapsules achieved synergistic corrosion inhibition through self-healing of the core, chloride binding and pozzolanic activity of the wall, which is helpful to realize the sustainable development of steels.
研究领域:
材料科学
·
腐蚀工程
·
水泥化学
·
纳米技术
·
表面改性
·
电化学
·
计算材料科学
✓ 已验证
DOI
高影响因子
APPLIED CLAY SCIENCE
·
2017
·
IF 3.101
Minwang Laipan,Haoyang Fu,Runliang Zhu,Luyi Sun,Rachel M. Steel,Sujuan Ye,Jianxi Zhu,Hongping He
Acid drainage (AD) poses a significant concern for water pollution due to its strong acidity and the toxicity of its various contaminants (e.g., heavy metal ions). In order to minimize the harmful effects of AD, the acidity must be neutralized and the contaminants be removed. The capacity of calcined Mg/Al layered double hydroxide (Mg/Al-CLDH) for simultaneously neutralizing the pH of AD and removing various heavy metal cations and oxyanions (Cr(VI) and phosphate) was studied herein. The interactions throughout co-removal between metal cations (in short M) and oxyanions were particularly investigated. In the solution with only M, Mg/Al-CLDH was capable of neutralizing solution pH and removing M. The reconstruction of LDH from Mg/Al-CLDH produced OH – to neutralize pH and partially remove M through precipitation. FT-IR results suggested that forming H-bonds with the reconstructed LDH (R-LDH) might also contribute to M removal. In the solution containing both M and oxyanions, M and oxyanions could mutually affect their removal efficiency by Mg/Al-CLDH. M weakened the removal capacities of Cr(VI) and phosphate, because it could compete for adsorption sites on R-LDH. Cr(VI) and phosphate showed complex effects on the removal of M: Low concentrations of Cr(VI) promoted the removal of M by providing extra adsorption sites; high concentrations of Cr(VI), however, had the opposite effect, as a high concentration of Cr(VI) might largely occupy the adsorption sites on R-LDH. By contrast, phosphate inhibited the removal of M considerably, which might be ascribed to its strong buffering ability that maintained a relatively strong acidic nature of the solution. Our results, for the first time, showed that Mg/Al-CLDH is particularly suitable for the treatment of AD containing various contaminants.
研究领域:
环境科学
·
化学工程
✓ 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）