Photocatalytic hydrogen evolution from biomass conversion

Abstract

Biomass has incredible potential as an alternative to fossil fuels for energy production that is sustainable for the future of humanity. Hydrogen evolution from photocatalytic biomass conversion not only produces valuable carbon-free energy in the form of molecular hydrogen but also provides an avenue of production for industrially relevant biomass products. This photocatalytic conversion can be realized with efficient, sustainable reaction materials (biomass) and inexhaustible sunlight as the only energy inputs. Reported herein is a general strategy and mechanism for photocatalytic hydrogen evolution from biomass and biomass-derived substrates (including ethanol, glycerol, formic acid, glucose, and polysaccharides). Recent advancements in the synthesis and fundamental physical/mechanistic studies of novel photocatalysts for hydrogen evolution from biomass conversion are summarized. Also summarized are recent advancements in hydrogen evolution efficiency regarding biomass and biomass-derived substrates. Special emphasis is given to methods that utilize unprocessed biomass as a substrate or synthetic photocatalyst material, as the development of such will incur greater benefits towards a sustainable route for the evolution of hydrogen and production of chemical feedstocks.

LaFeO3 Modified with Ni for Hydrogen Evolution via Photocatalytic Glucose Reforming in Liquid Phase

“…Already, typically used for the removal of organic contaminants from wastewater, the heterogeneous photocatalysis offers the opportunity to achieve molecular hydrogen production under the irradiation, by reforming of organic molecules in liquid phase. Indeed, in literature, it is reported that biomass photoreforming is a promising method for the molecular hydrogen production, not only because the method relies on predictably infinite solar energy inputs, but also it is based on a renewable biomass substrate and could use by-products of industrial biomass processes existing, e.g., ethanol from sugar fermentation [7,8]. The photoreforming process improves the well-known process of photocatalytic water-splitting [9] since the organic components acts as a hole scavengers, overcoming the main drawbacks of the water-splitting as unfavorable thermodynamics and rapid recombination of the O 2 and H 2 produced [10].…”

“…Cellulose behaves like a sacrificial agent through the depolymerization of cellulose into glucose products by oxidizing species and combines with the photo-generated oxidant species suppressing charge carrier recombination. In general, glucose represents one of the most efficient sacrificial substances for the photocatalytic production of hydrogen [8]. The photocatalytic production of hydrogen was studied for several years and there are many catalysts used for this purpose, such as TiO 2 based photocatalysts [12][13][14][15].…”

“…In particular, fluorine significantly enhanced the photocatalytic H 2 production due to the formation of unbounded •OH radicals that are more reactive [20]. Pt is often used also as doping element for titania: in this case, Pt is a robust proton reduction catalyst and an increase in H 2 production under irradiation can be observed, as evidence of the suppression of electron-hole recombination [8]. About this, the photocatalytic molecular hydrogen evolution from cellulose with Pt/TiO 2 under visible light irradiation was studied [8].…”

“…Pt is often used also as doping element for titania: in this case, Pt is a robust proton reduction catalyst and an increase in H 2 production under irradiation can be observed, as evidence of the suppression of electron-hole recombination [8]. About this, the photocatalytic molecular hydrogen evolution from cellulose with Pt/TiO 2 under visible light irradiation was studied [8]. Platinum is certainly one of the most performing elements to use (both on the surface and as a doping element), but it is also a very expensive noble metal.…”

Electrochemically induced deposition of hydroxyl‐terminated poly(amidoamine) dendrimers encapsulating Pt nanoparticles on indium tin oxide for enhanced electrochemiluminescence

“…Recently, we have reported the electrochemical surface modification of electrode materials including glassy carbon, carbon nanotube, and indium tin oxide (ITO) via electro‐oxidative coupling of amine‐terminated dendrimers 12–14 . The electrochemical modification of electrode surfaces with dendrimers has provided an effective and unique means for surface decoration of electrodes with catalytic nanoparticles because the dendrimers are capable of encapsulating various types of catalytic nanoparticles inside their internal cavity 15–19 . In order to further expand the scope of dendrimers for application in the electrochemical surface modification, our attention has been directed to hydroxyl‐terminated dendrimers as well.…”