Ultrathin Assembles of Porous Array for Enhanced H2 Evolution

Abstract

Since the complexity of photocatalyst synthesis process and high cost of noble cocatalyst leftovers a major hurdle to producing hydrogen (H 2 ) from water, a noble metal-free Ni-Si/MgO photocatalyst was realized for the first time to generate H 2 effectively under illumination with visible light. The catalyst was produced by means of simple one-pot solid reaction using self-designed metal reactor. The physiochemical properties of photocatalyst were identified by XRD, FESEM, HRTEM, EDX, UVvisible, XPS, GC and PL. The photocatalytic activities of Ni-Si/MgO photocatalyst at different nickel concentrations were evaluated without adjusting pH, applied voltage, sacrificial agent or electron donor. The ultrathin-nanosheet with hierarchically porous structure of catalyst was found to exhibit higher photocatalytic H 2 production than hexagonal nanorods structured catalyst, which suggests that the randomly branched nanosheets are more active surface to increase the light-harvesting efficiency due to its short electron diffusion path. The catalyst exhibited remarkable performance reaching up to 714 µmolh −1 which is higher among the predominant semiconductor catalyst. The results demonstrated that the photocatalytic reaction irradiated under visible light illumination through the production of hydrogen and hydroxyl radicals on metals. The outcome indicates an important step forward one-pot facile approach to prepare noble ultrathin photocatalyst for hydrogen production from water.Why do we need to promote hydrogen energy? The scientist lays out about four main reasons-energy-saving, minimal ecological impacts, energy security and industrial competitiveness. Industrially, fossil-fuel based hydrogen production process emits greenhouse gas to the environment 1 . The use of solar energy to produce hydrogen from water could accelerate the development of high-impact breakthrough clean energy technologies. By developing an optimal photocatalyst, scientists are searching for the ways of improving clean energy (H 2 ) production from water without producing greenhouse gases or having many adverse effects on the atmosphere.A variety of titanium dioxide (TiO 2 ) phases and nanostructures have been studied extensively for photocatalytic hydrogen production because of its earth-abundance, non-toxicity as well as thermal and chemical stability 1,2 . However, photoirradiated electron recombination and wide band gap of bare TiO 2 remain challenge on efficient hydrogen production. Much work has been directed towards the adaptation of noble Pd, Au metals on the TiO 2 metals 3-5 or through the use of sacrificial reagents 6 . Noble co-catalyst could serve as electron sinks to isolate the photogenerated electron-holes 3 . Moreover, noble metals assist to boost the reaction process by lowering over-potential for proton deduction 4 . Unfortunately, the state-of-the-art co-catalysts are still noble metals (e.g. Pt, Au, Pd) or their oxides that are rare and expensive. As a consequence, the discovery of robust, low-cost and earth-abundant co-catalyst...

Facile Fabrication of N‐Doped K2Nb2O6 Nanocrystals with Defective Pyrochlore Structure for Improved Visible‐Light Photocatalytic Hydrogen Production

“…Several structural or component modification strategies have been developed to design visible‐light active photocatalysts for water splitting, such as metal doping, structural control, phase transfer, bandgap regulation, and surface sensitization. [ 27–30 ] However, the modification and visible‐light photocatalytic H 2 evolution property of K 2 Nb 2 O 6 have rarely been studied. Thus, it is still a great challenge to develop an efficient strategy to prepare nanosized K 2 Nb 2 O 6 with excellent visible‐light response to overcome the shortcomings mentioned previously for future applications.…”

A snapshot of coal‐fired power generation in Bangladesh: A demand–supply outlook

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3D-printed flexible energy harvesting devices designed using non-layered two-dimensional natural tourmaline silicates

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