Review of one-dimensional and two-dimensional nanostructured materials for hydrogen generation

Abstract

Hydrogen is an attractive alternative to fossil fuels in terms of environmental and other advantages. Of the various production methods for H 2 , photocatalysis requires further development so that it can be applied economically on an industrial scale. One-and two-dimensional nanostructures in both pristine and modified forms have shown great potential as catalysts in the generation of H 2 . We review here recent developments in these nanostructure catalysts and their efficiency in the generation of H 2 under UV/visible/simulated solar light. Despite much research effort, many photocatalysts do not yet meet the practical requirements for the generation of H 2 , such as visible light activity. H 2 production is dependent on a variety of parameters and factors. To meet future energy demands, several challenges in H 2 production still need to be solved. We address here the factors that influence the efficiency of H 2 production and suggest alternatives. The nanostructures are classified based on their morphology and their efficiency is considered with respect to the influencing parameters. We suggest effective ways of engineering catalyst combinations to overcome the current performance barriers.

Comparative study of alcohols as sacrificial agents in H2 production by heterogeneous photocatalysis using Pt/TiO2 catalysts

“…The photoreforming process of methanol [eq.5], like that of the subsequent sacrificial agents, entails complex mechanisms that involve a series of steps in which different oxidation intermediates are produced, each of which contributes to the reduction of H + for the generation of H 2 [eqs. [6][7][8][9][10][11][12].…”

“…1] [11,12]. Normally, solutions of pollutants are used which capture more efficiently the holes and impede recombination of the e --h + pair.…”

One‐dimensional TiO2 Nanotube Photocatalysts for Solar Water Splitting

“…For hydrogen production, the conduction band (CB) level should be more negative than hydrogen production level (0 V) while the valence band (VB) should be more positive than water oxidation level (1.23 V) for efficient oxygen production from water by photo/photoelectro‐catalysis 68, 69, 70, 71. As we can see from band levels of various semiconductor materials ( Figure 2 a), TiO 2 is one of the most used semiconductors for hydrogen production as a result of their suitable band structures, low environmental impact and low toxicity, and high stability, while some other semiconductors such as SiC, CdS may not be suitable for water splitting because of the problem of photocorrsion 72, 73. In a photocatalytic water splitting process (Figure 2b), electrons at the valance band of TiO 2 are exicted to the conduction band upon UV illumination.…”

Two‐dimensional nanomaterials for photocatalytic water disinfection: recent progress and future challenges

“…Although a variety of reviews in the field of photocatalytic pathogen inactivation have been published, and the significance of architecture design of photocatalysts has been increasingly recognized, a comprehensive summary that specializes in 2D‐based photocatalysts for water sterilization is still lacking. In this review, a detailed overview of 2D nanomaterials for photocatalytic pathogen inactivation is presented by categories.…”