Yanmeng Cai,Yue Wang,Xinyu Han,Liwen Zhang,Shichang Xu,Jixiao Wang
The composites of carbon nanotube (CNT) and the conducting polymer polypyrrole (PPy) doped with dodecyl benzene sulfonate (DBS − ) and Cl − were prepared respectively by chemical oxidation method and made into two types of composite electrode (PPy-DBS/CNT and PPy-Cl/CNT) for capacitive deionization (CDI) cell. Enhanced electrochemical performance of the composite electrodes was confirmed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) test. The results of CV showed that the specific capacitance of PPy/CNT doped with either DBS − or Cl − was about 2.3–2.5 times that of the CNT electrode. And EIS test demonstrated that the charging resistance for both the PPy-DBS/CNT and PPy-Cl/CNT electrodes was dramatically reduced and only about 10% that of the CNT electrode. By pairing the two composite electrodes with CNT electrodes, four cells were assembled to study the effects of electrode assembling patterns on the desalination performance of the CDI process. The results indicated that the CDI cells involving either the PPy-DBS/CNT electrode or the PPy-Cl/CNT electrode, or both of them exhibited much higher electrosorption capacity (from 40.8 to 72.36 mg/g) than that of the CDI cell assembled with two CNT electrodes (about 12.6 mg/g). And the composite electrodes kept good stability and fast regeneration rate after several desalting cycles. Thus, it is believed that the enhanced performance and optimized electrode assembly of the CDI cell should be with the composite electrodes that have the good ability of ion selective adsorption for cations or anions.
A novel strategy to fabricate thin film nanocomposite (TFN) membrane was reported by dispersing nanofillers in the aqueous and organic phase simultaneously via interfacial polymerization of m-phenylenediamine and trimesoyl chloride. Two different nanofillers (hydrophilic MCM-48 and hydrophobic ZIF-8) were used to investigate the new strategy. Both hydrophilic MCM-48 and hydrophobic ZIF-8 can effectively improve the separation performance of the TFN membrane with higher water flux value maintaining high salt rejection via the novel strategy than conventional TFN membrane prepared with same total amount nanoparticles in singly organic phase or aqueous phase. It indicates that the new strategy is feasible to obtain the TFN membrane with excellence separation performance compared with the conventional method by dispersing nanofillers in singly phase. The new strategy is realized by dispersing less amount nanofillers in both phases simultaneously, which is possible to avoid the aggregation of nanoparticles and maximize the effect of nanoparticles.
Binglin Bai,Xiaohong Yang,Rui Tian,XuanXuan Wang,Haibo Wang
Solar steam generation has become the most promising solar-thermal applications in recent years. Scientists often focus on the search for superior materials, efficient structures, while ignoring the use of residual heat from the water at the bottom. In this paper, a membrane distillation system that utilizes residual heat was added in a new solar house of a domestic hot water and drinking water supply system in the first place. The pDA-rGO-PTFE membrane as an excellent evaporator was characterized in solar steam generation system, which possesses good hydrophilicity capacity and high intrinsic absorption properties . And at the optimal concentration of 20 mg/mL, the evaporation rate and efficiency of pDA-rGO-PTFE membrane could reach up 1.45 kg·m −2 ·h −1 and 93.8% respectively in one sun (one sun = 1kw·m −2 ). The PTFE membrane as a separator was applied in a membrane distillation system. Under average 0.66 sun in the natural environment, the average evaporation rate of a new solar house could reach about 1.10 kg·m −2 ·h −1 , and there is an additional 0.71 kg·m −2 ·h −1 membrane permeation flux by the residual heat. In addition, the new solar house showed an excellent durability and desalination ability, the ions rejection rations of the collected condensate water were close to 99.8%. Hence, we conclude that further ideas of a new solar house were provided for solving water scarcity, domestic water consumption and the application of solar steam generation in the future.
Xudong Bu,Yurong Zhang,Haiqing Guo,Sheng Wang,Xueyan Du
The ion removal capacity of carbon based capacitive deionization (CDI) is limited by the double-layer mechanism. Replacing one electrode of the conventional carbon-based symmetric CDI with a battery-like ion insertion material to obtain hybrid capacitive deionization (HCDI) can significantly improve the adsorption capacity . Various ion insertion materials have been adopted for HCDI, however, how to optimize the performance of the HCDI system by matching the two electrodes with different ions removal mechanism remains challenging. In this work, a HCDI desalination cell was demonstrated by using NaTi 2 (PO 4 ) 3 /reduced graphene oxide composites (NTP-rGO-700) as the cathode and activated carbon (AC) as the anode. Based on the mass balance strategy of electrodes and the electrochemical behavior of hybrid capacitors with different AC:NTP-rGO-700 mass ratios, the HCDI desalination cell was assembled with the optimal AC:NTP-rGO-700 mass ratio of 2:1. At an operating voltage of 1.6 V and a current density of 125 mA·g −1 , the specific adsorption capacity (SAC) of the HCDI cell can reach 51 mg·g −1 with an average salt adsorption rate (ASAR) of 2 mg·g −1 ·min −1 , and the energy consumption (E m ) is 136.53 kJ·mol −1 . This work provides an efficient approach for developing high performance HCDI cell.
危险品化学品经营许可证（带存储）