scholarly journals Superactive NiFe-LDH/graphene nanocomposites as competent catalysts for water splitting reactions

2020 ◽  
Vol 7 (20) ◽  
pp. 3805-3836 ◽  
Author(s):  
Susanginee Nayak ◽  
Kulamani Parida
Keyword(s):  
Catalytic Activity ◽  
Water Splitting ◽  
High Performance ◽  
Graphene Nanocomposites ◽  
Photocatalytic Water Splitting

Adaptable strategies for the design of superactive NiFe-LDH/graphene nanocomposites for high-performance catalytic activity towards electrocatalytic, photoelectrocatalytic, and photocatalytic water splitting have been reviewed.

scholarly journals Design of a Concentrator With a Rectangular Flat Focus and Operation With a Suspension Reactor for Experiments in the Field of Photocatalytic Water Splitting

2014 ◽  
Author(s):  
Michael Wullenkord ◽  
Christian Jung ◽  
Christian Sattler
Keyword(s):  
Water Splitting ◽  
High Performance ◽  
Performance Test ◽  
Test Facility ◽  
Angle Of Incidence ◽  
Solar Concentrator ◽  
Tracking Accuracy ◽  
Photocatalytic Water Splitting ◽  
Maximum Angle ◽  
Production Of Hydrogen

Photocatalytic water splitting is a potential route for future carbon-free production of hydrogen. However catalysts still need to be enhanced in order to reach acceptable solar-to-fuel efficiency. In the context of the project HyCats funded by the Federal Ministry of Education and Research of Germany a high performance test facility for the evaluation of the activity of photocatalysts under practical conditions was established. It mainly consists of a solar concentrator and a planar receiver reactor. A modified linear Fresnel concentrator configuration was chosen based on ray tracing simulation results and improved concerning the number of different facets and the tolerance of tracking errors. It meets the major demand of a homogeneous irradiance distribution on the surface of the reactor. The SoCRatus (Solar Concentrator with a Rectangular Flat Focus) is a 2-axis solar concentrator with a geometrical concentration ratio of 20.2 and an aperture area of 8.8 m2. The tracking accuracy is better than 0.1° respecting both the solar azimuth and altitude angle. Its 22 highly UV/Vis-reflective flat aluminum mirror facets reflect the sunlight resulting in a rectangular focus with a nominal width of 100 mm and a nominal length of 2500 mm. The reactor is placed in the focal plane at a distance of 2500 mm from the mounting plane of the facets and allows concentrated solar radiation to penetrate suspensions of water, electrolytes and photocatalyst particles flowing through it. Corresponding to a maximum angle of incidence of 36.6° the Quartz window reflects not more than 5% of the incoming radiation and assures only marginal absorption, particularly in the UV-part of the sun’s spectrum. The material of the receiver body is PTFE (polytetrafluoroethylene) providing reflection coefficients above 90% concerning wavelengths of UV-A and UV-B. The design of the reactor features two parallel reaction chambers, offering the possibility to test two separate suspensions at the same irradiation conditions. A pump transports the tempered suspension to the reactor. The geometry of the reactor inlet and outlet minimizes critical regions with inadequate flow caused by vortices. Any evolved gases are separated from the suspension in a tank together with nitrogen introduced in the piping upstream and are analyzed by micro chromatographs. Numerous devices are installed in order to control and monitor the reaction conditions. First experiments have been carried out using methanol as a sacrificial reagent.

In situ topotactic fabrication of direct Z-scheme 2D/2D ZnO/ZnxCd1−xS single crystal nanosheet heterojunction for efficient photocatalytic water splitting

2018 ◽  
Vol 8 (24) ◽  
pp. 6458-6467 ◽  
Author(s):  
Jingjing Shi ◽  
Shuangde Li ◽  
Fengming Wang ◽  
Yanmei Li ◽  
Lina Gao ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Single Crystal ◽  
Water Splitting ◽  
High Performance ◽  
Photocatalytic Water Splitting ◽  
Production Activity

The 2D/2D ZnO/ZnxCd1−xS single crystal nanosheet heterojunction exhibited high-performance hydrogen production activity.

A Rapid Solar Reduction Method to TiO2/MoO2/Graphene Nanocomposites for Photocatalytic Water Splitting

2015 ◽  
Vol 1738 ◽  
Author(s):  
Jyothirmayee Aravind.S.S ◽  
Kandalam Ramanujachary ◽  
Timothy D. Vaden ◽  
Amos Mugweru
Keyword(s):  
Water Splitting ◽  
Reduction Method ◽  
High Current Density ◽  
Phase Identification ◽  
Co Catalyst ◽  
Graphene Nanocomposites ◽  
Photocatalytic Water Splitting ◽  
Earth Abundant ◽  
Co Reduction ◽  
Interesting Area

ABSTRACTSemiconductor photocatalysis has emerged as an interesting area of research since the discovery of Honda-Fujishima effect. In this study, TiO2/MoO2/graphene composites have been prepared by a solar radiation-assisted co-reduction method, wherein ammonium tetrathiomolybdate salt and graphite oxide are reduced to MoO2 and graphene respectively along with TiO2. The method involved the utilization of focused pulses of natural sunlight using a simple convex lens, thereby eliminating the need for harmful reducing agents. The compound was characterized by XRD and SEM for phase identification and morphology. The TiO2/MoO2/graphene composite exhibits superior photocatalytic water splitting activity without using a co-catalyst. In addition, we demonstrate the electrocatalytic hydrogen production using this earth abundant catalyst, which shows high current density (60 mA/cm2) and low Tafel slope (47 mV/dec). The hydrogen evolved during photocatalysis was detected by gas chromatography.

Defective Two-dimensional Layered Heterometallic Phosphonate as Highly Efficient Oxygen Evolution Electrocatalyst

2021 ◽  
Author(s):  
Chong-Chong Yan ◽  
Sifu Tang
Keyword(s):  
Catalytic Activity ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
High Performance ◽  
Two Dimensional ◽  
Metal Phosphonates ◽  
Highly Efficient

High-performance nonprecious electrocatalysts toward water splitting are highly demanded but currently it is still challenging. Here, we demonstrate that heterometallic two-dimensional (2D) metal phosphonates with improved catalytic activity and durability...

Efficient and stable charge transfer channels for photocatalytic water splitting activity of CdS without sacrificial agents

2020 ◽  
Vol 8 (40) ◽  
pp. 20963-20969 ◽  
Author(s):  
Wei Chen ◽  
Guo-Bo Huang ◽  
Hao Song ◽  
Jian Zhang
Keyword(s):  
Charge Transfer ◽  
Water Splitting ◽  
Photocatalytic Water Splitting ◽  
Transfer Channel ◽  
Efficient Charge ◽  
Transfer Channels

An efficient charge transfer channel for improving the photocatalytic water splitting activity and durability of CdS without sacrificial agents.

scholarly journals Recent Achievements in Development of TiO2-Based Composite Photocatalytic Materials for Solar Driven Water Purification and Water Splitting

Materials ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1338 ◽  
Author(s):  
Klara Perović ◽  
Francis M. dela Rosa ◽  
Marin Kovačić ◽  
Hrvoje Kušić ◽  
Urška Lavrenčič Štangar ◽  
...  
Keyword(s):  
Water Treatment ◽  
Transition Metal ◽  
Photocatalytic Degradation ◽  
Water Splitting ◽  
Water Purification ◽  
Degradation Mechanism ◽  
Living Environment ◽  
Solar Irradiation ◽  
Metal Chalcogenides ◽  
Photocatalytic Water Splitting

Clean water and the increased use of renewable energy are considered to be two of the main goals in the effort to achieve a sustainable living environment. The fulfillment of these goals may include the use of solar-driven photocatalytic processes that are found to be quite effective in water purification, as well as hydrogen generation. H2 production by water splitting and photocatalytic degradation of organic pollutants in water both rely on the formation of electron/hole (e−/h+) pairs at a semiconducting material upon its excitation by light with sufficient photon energy. Most of the photocatalytic studies involve the use of TiO2 and well-suited model compounds, either as sacrificial agents or pollutants. However, the wider application of this technology requires the harvesting of a broader spectrum of solar irradiation and the suppression of the recombination of photogenerated charge carriers. These limitations can be overcome by the use of different strategies, among which the focus is put on the creation of heterojunctions with another narrow bandgap semiconductor, which can provide high response in the visible light region. In this review paper, we report the most recent advances in the application of TiO2 based heterojunction (semiconductor-semiconductor) composites for photocatalytic water treatment and water splitting. This review article is subdivided into two major parts, namely Photocatalytic water treatment and Photocatalytic water splitting, to give a thorough examination of all achieved progress. The first part provides an overview on photocatalytic degradation mechanism principles, followed by the most recent applications for photocatalytic degradation and mineralization of contaminants of emerging concern (CEC), such as pharmaceuticals and pesticides with a critical insight into removal mechanism, while the second part focuses on fabrication of TiO2-based heterojunctions with carbon-based materials, transition metal oxides, transition metal chalcogenides, and multiple composites that were made of three or more semiconductor materials for photocatalytic water splitting.

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