期刊：
International Journal of Hydrogen Energy,2019年44(2):594-604 ISSN：0360-3199
通讯作者：
Li, Jie;Li, Wenzhang
作者机构：
[Qiu, Xiaoqing; Yin, Xiang; Li, Jie; Liu, Qiong; Wang, Keke; Liu, Yang; Li, Wenzhang] Cent South Univ, Sch Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;[Li, Wenzhang] Cent South Univ, Hunan Prov Key Lab Efficient & Clean Utilizat Man, Changsha 410083, Hunan, Peoples R China.;[Li, Yaomin] UCL, Dept Chem, 20 Gordon St, London WC1H 0AJ, England.;[Liu, Yang] Hunan Agr Univ, Coll Resources & Environm, Changsha 410128, Hunan, Peoples R China.;[Li, Dongwei] Chongqing Univ Educ, Div Sci Res Management, Chongqing 400065, Peoples R China.
通讯机构：
[Li, Jie; Li, Wenzhang] C;Cent South Univ, Sch Chem & Chem Engn, Changsha 410083, Hunan, Peoples R China.;Cent South Univ, Hunan Prov Key Lab Efficient & Clean Utilizat Man, Changsha 410083, Hunan, Peoples R China.
关键词：
Bias voltage;Copper oxides;Efficiency;Electrochemistry;Hydrogen;Iron compounds;Photocathodes;Photocurrents;Photoelectrochemical cells;Solar power generation;Titanium dioxide;Current density-voltage curves;Photoconversion efficiency;Photoelectrochemicals;Solar hydrogen;Solar water splitting;Tandem cells;Two-electrode systems;Water splitting;Bismuth compounds
摘要：
An integrated solar water splitting tandem cell without external bias was designed using a FeOOH modified TiO2/BiVO4 photoanode as a photoanode and p-Cu2O as a photo-cathode in this study. An apparent photocurrent (0.37 mA/cm(2) at operating voltage of +0.36 V-RHE) for the tandem cell without applied bias was measured, which is corresponding to a photoconversion efficiency of 0.46%. Besides, the photocurrent of FeOOH modified TiO2/BiVO4 Cu2O is much higher than the operating point given by pure BiVO4 and Cu2O photocathode (-0.07 mA/cm(2) at +0.42 VRHE). Then we established a FeOOH modified TiO2/BiVO4 Cu2O two-electrode system and measured the current density voltage curves under AM 1.5G illumination. The unassisted photocurrent density is 0.12 mA/cm(2) and the corresponding amounts of hydrogen and oxygen evolved by the tandem PEC cell without bias are 2.36 umol/cm(2) and 1.09 urnol/cm(2) after testing for 2.5 h. The photoelectrochemical (PEC) properties of the FeOOH modified TiO2/BiVO4 photoanode were further studied to demonstrate the electrons transport process of solar water splitting. This aspect provides a fundamental challenge to establish an unbiased and stabilized photoelectrochemical (PEC) solar water splitting tandem cell with higher solar to -hydrogen efficiency. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
摘要：
Abiotic stress induces nitrate (NO3 (-)) allocation to roots, which increases stress tolerance in plants. NRT1.1 is broadly involved in abiotic stress tolerance in plants, but the relationship between NRT1.1 and NO3 (-) allocation under stress conditions is unclear. In this study, we found that Arabidopsis wild-type Col-0 was more cadmium (Cd(2+))-tolerant than the nrt1.1 mutant at 20 muM CdCl2. Cd(2+) exposure repressed NRT1.5 but upregulated NRT1.8 in roots of Col-0 plants, resulting in increased NO3 (-) allocation to roots and higher [NO3 (-)] root-to-shoot (R:S) ratios. Interestingly, NITRATE REGULATORY GENE2 (NRG2) was upregulated by Cd(2+) stress in Col-0 but not in nrt1.1. Under Cd(2+) stress, nrg2 and nrg2-3chl1-13 mutants exhibited similar phenotypes and NO3 (-) allocation patterns as observed in the nrt1.1 mutant, but overexpression of NRG2 in Col-0 and nrt1.1 increased the [NO3 (-)] R:S ratio and restored Cd(2+) stress tolerance. Our results indicated that NRT1.1 and NRG2 regulated Cd(2+) stress-induced NO3 (-) allocation to roots and that NRG2 functioned downstream of NRT1.1. Cd(2+) uptake did not differ between Col-0 and nrt1.1, but Cd(2+) allocation to roots was higher in Col-0 than in nrt1.1. Stressed Col-0 plants increased Cd(2+) and NO3 (-) allocation to root vacuoles, which reduced their cytosolic allocation and transport to the shoots. Our results suggest that NRT1.1 regulates NO3 (-) allocation to roots by coordinating Cd(2+) accumulation in root vacuoles, which facilitates Cd(2+) detoxification.
作者机构：
[黄思怡] College of Resources and Environment, Hunan Agricultural University/National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Changsha, 410128, China;Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha, 410128, China;[周旋] Hunan Institute of Soil and Fertilizer, Changsha, 410125, China;[谢桂先; 刘强; 田昌; 张玉平; 彭建伟; 荣湘民] College of Resources and Environment, Hunan Agricultural University/National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Changsha, 410128, China, Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha, 410128, China
通讯机构：
[Zhang, Y.-P.] C;College of Resources and Environment, China
摘要：
A high concentration of ammonium (NH4+) as the sole source of nitrogen in the growth medium often is toxic to plants. The nitrate transporter NRT1.1 is involved in mediating the effects of NH4+ toxicity; however, the mechanism remains undefined. In this study, wild-type Arabidopsis (Arabidopsis thaliana Columbia-0 [Col-0]) and NRT1.1 mutants (chl1-1 and chl1-5) were grown hydroponically in NH4NO3 and (NH4)(2)SO4 media to assess the function of NRT1.1 in NH4+ stress responses. All the plants grew normally in medium containing mixed nitrogen sources, but Col-0 displayed more chlorosis and lower biomass and photosynthesis than the NRT1.1 mutants in (NH4)(2)SO4 medium. Grafting experiments between Col-0 and chli-5 further confirmed that NH4+ toxicity is influenced by NRT1.1. In (NHASO, medium, NRT1.1 induced the expression of NH4+ transporters, increasing NH4+ uptake. Additionally, the activities of glutamine synthetase and glutamate synthetase in roots of Col-0 plants decreased and soluble sugar accumulated significantly, whereas pyruvate kinase-mediated glycolysis was not affected, all of which contributed to NH4+ accumulation. By contrast, the NRT1.1 mutants showed reduced NH4+ accumulation and enhanced NH4+ assimilation through glutamine synthetase, glutamate synthetase, and glutamate dehydrogenase. Moreover, the up-regulation of genes involved in ethylene synthesis and senescence in Col-0 plants treated with (NH4)(2)SO4 suggests that ethylene is involved in NH4+ toxicity responses. This study showed that NH4+ toxicity is related to a nitrate-independent signaling function of NRT1.1 in Arabidopsis, characterized by enhanced NH4+ accumulation and altered NH4+ metabolism, which stimulates ethylene synthesis, leading to plant senescence.
作者机构：
[谭力彰] College of Resources and Environment, Hunan Agricultural University, National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Changsha, 410128, China;Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha, 410128, China;[周旋] Soil and Fertilizer Institute of Hunan Province, Changsha, 410125, China;[田昌; 张玉平; 彭建伟; 刘强; 荣湘民; 谢桂先] College of Resources and Environment, Hunan Agricultural University, National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, Changsha, 410128, China, Southern Regional Collaborative Innovation Center for Grain and Oil Crops in China, Changsha, 410128, China
通讯机构：
[Xie, G.] C;College of Resources and Environment, China
摘要：
Oxygen vacancy, as a kind of self-doping strategy, has been considered by numerous researchers. Several papers have been published about introducing oxygen vacancies in the semiconductors, which give a viewpoint that the concentration of oxygen vacancies may influence the performance. But few of them focus on how to control the concentration of oxygen vacancies, and how to achieve the goal without using additional equipment (such as sealed tube furnace) for too long time (20 min-4 h without considering the time for rising temperature and cooling). In this paper, oxygen vacancies were introduced into the WO3 vertically plate-like arrays films in a short time by chemical reduction. TiCl3 solutions with different concentrations were used as the reductant, and the concentration of oxygen vacancies of WO3 was proportional to the concentration of TiCl3. After importing oxygen vacancies, WO3 film photoanode showed enhanced photoelectrochemical performance, and the photocurrent of treated WO3 (0.88 mA/cm(2) at 1.2 V vs. Ag/AgCl) was 1.27 times that of pristine WO3 (0.69 mA/cm(2)). However, the photocurrent decreased when the concentration of TiCl3 was too high. The over importation of oxygen vacancies might result in a thicker disorder layer with surface defects and more recombination centers. In such a situation, there was an unsatisfactory transfer and separation ability of photogenerated charges. This study provides new insight into controlling the concentration of oxygen vacancies via a rapid and easy approach. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
