scholarly journals Enhanced hydrogen production of Rhodobacter sphaeroides promoted by extracellular H+ of Halobacterium salinarum

2021 ◽  
Vol 71 (1) ◽  
Author(s):  
Jiang-Yu Ye ◽  
Yue Pan ◽  
Yong Wang ◽  
Yi-Chao Wang

Abstract Purpose This study utilized the principle that the bacteriorhodopsin (BR) produced by Halobacterium salinarum could increase the hydrogen production of Rhodobacter sphaeroides. H. salinarum are co-cultured with R. sphaeroides to determine the impact of purple membrane fragments (PM) on R. sphaeroides and improve its hydrogen production capacity. Methods In this study, low-salinity in 14 % NaCl domesticates H salinarum. Then, 0–160 nmol of different concentration gradient groups of bacteriorhodopsin (BR) and R. sphaeroides was co-cultivated, and the hydrogen production and pH are measured; then, R. sphaeroides and immobilized BR of different concentrations are used to produce hydrogen to detect the amount of hydrogen. Two-chamber microbial hydrogen production system with proton exchange membrane-assisted proton flow was established, and the system was operated. As additional electricity added under 0.3 V, the hydrogen production rate increased with voltages in the coupled system. Results H salinarum can still grow well after low salt in 14% NaCl domestication. When the BR concentration is 80 nmol, the highest hydrogen production reached 217 mL per hour. Both immobilized PC (packed cells) and immobilized PM (purple membrane) of H. salinarum could promote hydrogen production of R. sphaeroides to some extent. The highest production of hydrogen was obtained by the coupled system with 40 nmol BR of immobilized PC, which increased from 127 to 232 mL, and the maximum H2 production rate was 18.2 mL−1 h−1 L culture. In the 192 h experiment time, when the potential is 0.3 V, the hydrogen production amount can reach 920 mL, which is 50.3% higher than the control group. Conclusions The stability of the system greatly improved after PC was immobilized, and the time for hydrogen production of R. sphaeroides significantly extended on same condition. As additional electricity added under 0.3 V, the hydrogen production rate increased with voltages in the coupled system. These results are helpful to build a hydrogen production-coupled system by nitrogenase of R. sphaeroides and proton pump of H. salinarum. Graphical abstract

2015 ◽  
Vol 98 ◽  
pp. 383-389 ◽  
Author(s):  
Chiung-Yi Cheng ◽  
Kuang-Li Cheng ◽  
Terng-Jou Wan ◽  
Wei-Nung Kuo ◽  
Feng-Jen Chu ◽  
...  

Nanoscale ◽  
2017 ◽  
Vol 9 (43) ◽  
pp. 17029-17036 ◽  
Author(s):  
Arka Saha ◽  
Apurba Sinhamahapatra ◽  
Tong-Hyun Kang ◽  
Subhash C. Ghosh ◽  
Jong-Sung Yu ◽  
...  

An efficient ‘noble metal free’ hydrogenated MoS2 QD-TiO2 heterojunction photocatalyst with a superior hydrogen production rate of 3.1 mmol g−1 h−1 is reported.


2014 ◽  
Vol 50 (14) ◽  
pp. 1731-1734 ◽  
Author(s):  
Zheng Wang ◽  
Jungang Hou ◽  
Chao Yang ◽  
Shuqiang Jiao ◽  
Hongmin Zhu

Three-dimensional MoS2–CdS–γ-TaON hollow nanostructures as novel photocatalysts were firstly synthesized via a facile hydrothermal method and they exhibit a high photocatalytic hydrogen production rate without a noble metal.


Author(s):  
Alicia Keow ◽  
Zheng Chen

Abstract Proton exchange membrane (PEM) electrolyzers with the ability to produce gases at a pressure suitable for direct metal hydride storage are desirable because they do not require the use of compressors and other auxiliary components. Direct storage into metal hydride cylinders is made feasible when the pressure and flow rate of hydrogen is controlled. The nonlinear dynamics of the PEM electrolyzer change with temperature and pressure, both of which change with the hydrogen production rate, and are thus difficult to estimate. Therefore, a model-free, relay-feedback, auto-tuning approach is used to tune a proportional integral (PI) controller. This allows for the determination of the voltage supply to the electrolyzer by tracking the current set-point and correlating it to the hydrogen production rate. A gain scheduling approach is used to record the tuned controller’s parameters at different set-points, minimizing the frequency of tuning the device. A self-assessment test is used to determine situations where the auto-tuner should activate to update the PI parameters, thus, allowing for the system to operate without supervision. The auto-tuning PI control is successfully tested with a PEM electrolyzer setup. Experimental results showed that an auto-tuner can tune the controller parameters and produce favorable transient behaviors, allowing for a degree of adaptability for variations in system set-points.


Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 451 ◽  
Author(s):  
Jai-Houng Leu ◽  
Ay Su ◽  
Jung-Kang Sun ◽  
Zhen-Ming Huang

The research in this study focused on the operating parameters for a high efficiency hydrogen production rate system, with the aim to design a hydrolysis of the NaBH4 hydrogen production module for lightweight and efficient hydrogen production and conversion. The experiment used a reactor, where the reaction volume was about 12 mL. The parameters on the feed rate of the NaBH4 solution and the catalyst loading for the hydrogen production rate and conversion efficiency were investigated. The catalyst is sufficient to allow the release of hydrogen in the 1 g/min solution, but the efficiency of hydrogen production at high flow rates has been shown to be low in previous studies. Therefore, the aim is to increase the catalyst to improve the reaction efficiency in this study. The results show that at the high temperature reaction condition, solid NaBO2 will not generate on the catalyst surface to influence the hydrogen production rate when using the five pcs catalyst. When the reaction temperature was 108 °C, the average hydrogen production rate was 1.72 L/min, and the conversion efficiency was 91.2%.


2022 ◽  
Author(s):  
Xiyu Deng ◽  
Xinya Kuang ◽  
Jiyang Zeng ◽  
Baoye Zi ◽  
Yiwen Ma ◽  
...  

Abstract Photocatalytic water splitting is considered to be a feasible method to replace traditional energy. However, most of the catalysts have unsatisfactory performance. In this work, we used a hydrothermal process to grow Ag nanoparticles in situ on g-C3N4 nanosheets, and then a high performance catalyst (Ag- g-C3N4) under visible light was obtained. The Ag nanoparticles obtained by this process are amorphous and exhibit excellent catalytic activity. At the same time, the local plasmon resonance effect of Ag can effectively enhance the absorption intensity of visible light by the catalyst. The hydrogen production rate promote to 1035 μmol g-1h-1 after loaded 0.6 wt% of Ag under the visible light, which was 313 times higher than that of pure g-C3N4 (3.3μmol g-1h-1). This hydrogen production rate is higher than most previously reported catalysts which loaded with Ag or Pt. The excellent activity of Ag- g-C3N4 is benefited from the Ag nanoparticles and special interaction in each other. Through various analysis and characterization methods, it is shown that the synergy between Ag and g-C3N4 can effectively promote the separation of carriers and the transfer of electrons. Our work proves that Ag- g-C3N4 is a promising catalyst to make full use of solar energy.


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