To effectively treat pollution and overcome the lack of selectivity of TiO_(2)-based photocatalysts,a 1D structure and molecular imprinting technology have been combined to produce TiO_(2)/SiO_(2) hybrid fibers by a s...To effectively treat pollution and overcome the lack of selectivity of TiO_(2)-based photocatalysts,a 1D structure and molecular imprinting technology have been combined to produce TiO_(2)/SiO_(2) hybrid fibers by a simple electrospinning method by directly adding templates into the precursor solution.In our design,TBOT acts as a titanium source and a functional monomer to combine with RhB and generate specific recognition sites,and SiO_(2) plays a role in inhibiting phase transition.The calcination process can not only remove the template and form an imprinting cavity but also enhance the crystallinity of photoca-talysts.The inorganic framework also overcomes the shortcomings of the instability of traditional organic molecularly imprinted layers.In contrast to a nonimprinted sample,imprinted fibers exhibit higher adsorp-tion capacity and selectivity,attributed to the specific combination through hydrogen bonds and space matching effect.The photocatalytic efficiency of the imprinted sample reached 100%within only 15 min,showing excellent photocatalytic performance and high selectivity.This work not only provides a novel,simple method to fabricate TiO_(2) fiber photocatalysts with high selectivity for the first time but also offers new strategies for the effective and selective treatment of pollutants in wastewater.展开更多
A membrane reactor for steam methane reforming heated by molten salt(MS-SMRMR)is studied based on finite time thermodynamics for decreasing carbon emissions and improving hydrogen production rate(HPR).Effects of flow ...A membrane reactor for steam methane reforming heated by molten salt(MS-SMRMR)is studied based on finite time thermodynamics for decreasing carbon emissions and improving hydrogen production rate(HPR).Effects of flow directions of sweep gas and molten salt on MS-SMRMR are researched.Profiles of temperatures,HPR,and local entropy generation rates(EGRs)of MS-SMRMR are analyzed.Hybrid particle swarm optimization algorithm is utilized to obtain the minimum of specific EGR(SEGR),ratio of EGR to HPR.Multi-objective optimization about HPR maximization and EGR minimization is performed by utilizing NSGA-II.The EGR caused by the mass transfer process is the largest among all irreversible processes in the MS-SMRMR.The membrane length should be slightly shorter than the reactor length when the flow direction of sweep gas is different from that of reaction mixture.When flow directions of molten salt and sweep gas are opposite to that of reaction mixture,SEGR is the smallest.Compared with SEGR calculated by utilizing initial parameters,SEGRs after primary,twice and triple optimizations reduce by 1.2%,5.5%and 5.7%,respectively.SEGR can be further decreased by adjusting other operating parameters.Pareto front provides many optimization results,and it contains SEGR minimization.In Pareto front,an optimum decision point is obtained based on decision-making of TOPSIS,and its EGR and HPR,respectively,increase by 7.12%and13.24%,compared with those obtained by using initial parameters.The results have certain theoretical guiding significance for optimization designs of MS-SMRMR.展开更多
基金supported by the National Natural Science Foundation of China(52073120).
文摘To effectively treat pollution and overcome the lack of selectivity of TiO_(2)-based photocatalysts,a 1D structure and molecular imprinting technology have been combined to produce TiO_(2)/SiO_(2) hybrid fibers by a simple electrospinning method by directly adding templates into the precursor solution.In our design,TBOT acts as a titanium source and a functional monomer to combine with RhB and generate specific recognition sites,and SiO_(2) plays a role in inhibiting phase transition.The calcination process can not only remove the template and form an imprinting cavity but also enhance the crystallinity of photoca-talysts.The inorganic framework also overcomes the shortcomings of the instability of traditional organic molecularly imprinted layers.In contrast to a nonimprinted sample,imprinted fibers exhibit higher adsorp-tion capacity and selectivity,attributed to the specific combination through hydrogen bonds and space matching effect.The photocatalytic efficiency of the imprinted sample reached 100%within only 15 min,showing excellent photocatalytic performance and high selectivity.This work not only provides a novel,simple method to fabricate TiO_(2) fiber photocatalysts with high selectivity for the first time but also offers new strategies for the effective and selective treatment of pollutants in wastewater.
基金supported by the National Natural Science Foundation of China(Grant Nos.51976235 and 51606218)the Hubei Province Natural Science Foundation of China(Grant No.2018CFB708)the Self-Topic Project of Naval University of Engineering(Grant No.20161504)。
文摘A membrane reactor for steam methane reforming heated by molten salt(MS-SMRMR)is studied based on finite time thermodynamics for decreasing carbon emissions and improving hydrogen production rate(HPR).Effects of flow directions of sweep gas and molten salt on MS-SMRMR are researched.Profiles of temperatures,HPR,and local entropy generation rates(EGRs)of MS-SMRMR are analyzed.Hybrid particle swarm optimization algorithm is utilized to obtain the minimum of specific EGR(SEGR),ratio of EGR to HPR.Multi-objective optimization about HPR maximization and EGR minimization is performed by utilizing NSGA-II.The EGR caused by the mass transfer process is the largest among all irreversible processes in the MS-SMRMR.The membrane length should be slightly shorter than the reactor length when the flow direction of sweep gas is different from that of reaction mixture.When flow directions of molten salt and sweep gas are opposite to that of reaction mixture,SEGR is the smallest.Compared with SEGR calculated by utilizing initial parameters,SEGRs after primary,twice and triple optimizations reduce by 1.2%,5.5%and 5.7%,respectively.SEGR can be further decreased by adjusting other operating parameters.Pareto front provides many optimization results,and it contains SEGR minimization.In Pareto front,an optimum decision point is obtained based on decision-making of TOPSIS,and its EGR and HPR,respectively,increase by 7.12%and13.24%,compared with those obtained by using initial parameters.The results have certain theoretical guiding significance for optimization designs of MS-SMRMR.
