Different forms of hydrogen production: a review and future perspectives

There was a significant increase in the concern with climate issues, among them highlighted as the derivation of greenhouse gases from the burning fossil fuels, leading several research centers and researchers to seek new sources of less polluting energy, independent of the burn-based matrix of fuels. In this context, the present work has as main presenter a literature review, perspective and comparisons regarding the use of hydrogen as a clean energy source, presenting three main ways of obtaining it: a) through electrolysis using renewable sources; b) biohydrogen production, based on the photosynthesis of plants and algae; c) production through biodigesters.

Straightforward synthesis of quinazolin-4(3H)-ones via visible light-induced condensation cyclization

Visible light was used as a readily available and renewable clean energy source for the green and metal catalyst free synthesis of quinazolin-4(3H)-ones. High and excellent yields of the desired products were obtained with good functional group tolerance.

A Facile Room-Temperature Fabrication of Silver-Platinum Nanocoral Catalyst Towards Hydrogen Evolution And Methanol Electro-Oxidation

With the rising energy demand and growing environmental problems, the produced hydrogen from electrolyzing water has emerged as the most sustainable and clean energy source that can alter to fossil...

Smart Designs of Mo Based Electrocatalysts for Hydrogen Evolution Reaction

As a sustainable and clean energy source, hydrogen can be generated by electrolytic water splitting (i.e., a hydrogen evolution reaction, HER). Compared with conventional noble metal catalysts (e.g., Pt), Mo based materials have been deemed as a promising alternative, with a relatively low cost and comparable catalytic performances. In this review, we demonstrate a comprehensive summary of various Mo based materials, such as MoO2, MoS2 and Mo2C. Moreover, state of the art designs of the catalyst structures are presented, to improve the activity and stability for hydrogen evolution, including Mo based carbon composites, heteroatom doping and heterostructure construction. The structure–performance relationships relating to the number of active sites, electron/ion conductivity, H/H2O binding and activation energy, as well as hydrophilicity, are discussed in depth. Finally, conclusive remarks and future works are proposed.

Nanostructured Photothermal Materials for Environmental and Catalytic Applications

Solar energy is a green and sustainable clean energy source. Its rational use can alleviate the energy crisis and environmental pollution. Directly converting solar energy into heat energy is the most efficient method among all solar conversion strategies. Recently, various environmental and energy applications based on nanostructured photothermal materials stimulated the re-examination of the interfacial solar energy conversion process. The design of photothermal nanomaterials is demonstrated to be critical to promote the solar-to-heat energy conversion and the following physical and chemical processes. This review introduces the latest photothermal nanomaterials and their nanostructure modulation strategies for environmental (seawater evaporation) and catalytic (C1 conversion) applications. We present the research progress of photothermal seawater evaporation based on two-dimensional and three-dimensional porous materials. Then, we describe the progress of photothermal catalysis based on layered double hydroxide derived nanostructures, hydroxylated indium oxide nanostructures, and metal plasmonic nanostructures. Finally, we present our insights concerning the future development of this field.

Hydrogen as a Clean Energy Source

Sustainable development of the world is mainly dependent on the use of present energy resources, which primarily includes water, wind, solar, geothermal, and nuclear power. Hydrogen as a clean and green energy source can be the resolution of the energy challenge and may satisfy the demands of several upcoming generations. Hydrogen when used it does not produce any type of pollutant and this makes it a best candidate as a clean energy. Hydrogen energy can be generated from natural gas, oil, biomass, and fossil fuels using thermochemical, photocatalytic, microbiological and electrolysis processes. Large scale hydrogen production is also testified up to some extent with proper engineering for multi applications. Alas, storage and transportation of hydrogen are the main challenge amongst scientific community. Photocatalytic hydrogen production with good efficiencies and amount is well discussed. Till date, using a variety of metal oxide-sulfide, carbon-based materials, metal organic frameworks are utilized by doping or with their composites for enhance the hydrogen production. Main intents of this chapter are to introduce all the possible areas of hydrogen applications and main difficulties of hydrogen transportation, storage and achievements in the hydrogen generation with its applications.

Degradation of Anti-Inflammatory Drugs in Synthetic Wastewater by Solar Photocatalysis

Due to the high number of anti-inflammatory drugs (AIMDs) used by the public health sector in Iraq and distributed all over the country and due to their toxicity, there is a need for an environmental-friendly technique to degrade any wasted (AIMD) present in aquatic ecosystem. The degradation of diclofenac sodium (DCF), ibuprofen (IBN), and mefenamic acid (MFA) in synthetic hospital wastewater were investigated utilizing locally-made Cu-coated TiO2 nanoparticles in a solar-irradiated reactor. Different key variables were studied for their effects on process efficiency, such as loadings of catalyst (C CU-TiO2 = 100–500 mg/L), AIMDs (100 µg/L), pH (4–9), and hydrogen peroxide (CH2O2 = 200–800 mg/L). The results revealed that degradation percentages of 96.5, 94.2, and 82.3%, were obtained for DCF, IBN, and MFA, respectively, using our Cu-coated TiO2 catalyst within 65 min at pH = 9, while other parameters were C CU-TiO2 = 300 mg/L, and CH2O2 = 400 mg/L. The experimental results revealed coupling photocatalysis with solar irradiation as a clean energy source could be utilized for the degradation of toxic pollutants in surface water.

A Review of Corrosion Resistance Alloy Weld Overlay Cladding Material for Geothermal Applications

Geothermal is known as renewable energy and a clean energy source but inherent properties make this energy clean. Minerals and deposits in geothermal reservoirs create a scale that is persistent in its corrosive nature. In addition, heat extremes and pressure variations present challenges to the integrity of the wellhead components and the downhole casing. Such challenges need to be mitigated to achieve maximum output from these aging or even newly commissioned wells. The geothermal power industry has reported a wide range of corrosion problems. Given the highly corrosive conditions to be treated in the geothermal sector and the benefits of reduced unplanned downtime, operating cost savings would be expected if more CRAs clad products were used. In many cases, only the material's surface requires corrosion resistance and carbon or alloy steel can be clad with a more corrosion-resistant alloy. Up to 80% of the cost of using solid alloy can be saved by cladding. Carbon or low-alloy steel cladding can be carried out by overlay welding. This paper reviews available literature on corrosion in the geothermal environment and presents the successful use of clad products in other industries to support the rising demand for Philippine geothermal applications.

Base dependent 1,3-dithioacetals rearrangement over sulfoxidation under visible-light photocatalysis to access disulfide-linked-dithioesters

Base dependent oxidative rearrangement of dithiolanes and dithianes to access disulfide-linked-dithioesters under visible-light photoredox catalytic conditions has been disclosed. The protocol demonstrated the ability to synthesize either rearranged product or sulfoxide by simply switching the base with inherent ability to make hydrogen bonding with sulfur atom. Unlike, the usual deprotection of thioacetals to corresponding aldehydes under the oxidative conditions, we observed the unique regioselective oxidative reactivity of thioacetals to form disulfide-linked-dithioester or sulfoxides. The generality of the protocol has been demonstrated by exploring a wide range of substrates. As an application the in-situ generated thyil radical has been trapped with disulfides to prepare hetro-disulfides of potential utility. The protocol proved to be practical on gram scale quantity and relied on clean energy source for the transformation. Based on the series of control experiments, cyclic volametry and Stern-Volmer studies the plausible mechanism has been proposed.