Hydrogen production by Tuning the Photonic Band Gap with the Electronic Band Gap of TiO2

Abstract

Tuning the photonic band gap (PBG) to the electronic band gap (EBG) of Au/TiO2 catalysts resulted in considerable enhancement of the photocatalytic water splitting to hydrogen under direct sunlight. Au/TiO2 (PBG-357 nm) photocatalyst exhibited superior photocatalytic performance under both UV and sunlight compared to the Au/TiO2 (PBG-585 nm) photocatalyst and both are higher than Au/TiO2 without the 3 dimensionally ordered macro-porous structure materials. The very high photocatalytic activity is attributed to suppression of a fraction of electron-hole recombination route due to the co-incidence of the PBG with the EBG of TiO2 These materials that maintain their activity with very small amount of sacrificial agents (down to 0.5 vol.% of ethanol) are poised to find direct applications because of their high activity, low cost of the process, simplicity and stability.

On the role of metal particle size and surface coverage for photo-catalytic hydrogen production: A case study of the Au/CdS system

“…A range of catalysts from simple binary metal oxides and metal sulfides to more complicated catalysts have been developed to achieve this objective [4][5][6]. TiO 2 [7][8][9][10][11][12][13] and CdS [14][15][16][17][18] attract special interest in this regard because of the relative simplicity of their chemical structure in addition to their stability. TiO 2 is one of the most stable and active photo-catalyst known, [6,13,18,19] though it suffers from the limitation of its light absorption range mostly in the UV region of solar spectrum (anatase E g = 3.2 eV, rutile E g = 3.0 eV).…”

Mechanical properties of Al2O3 inverse opals by means of nanoindentation

“…Inverse opal materials are gaining interest as photonic crystals [1], catalytic supports, capacitors [2], and photocatalytic devices [3], among others. Although it is possible to fabricate inverse opals by lithographic or ion beam techniques [4], self-assembly process is more flexible and cost effective for production [5,6,7].…”

Hydrogen Photoproduction from Ethanol–Water Mixtures Over Au–Cu Alloy Nanoparticles Supported on TiO2

“…In particular, deposition of Pt, Au, Pd and Ag nanoparticles onto TiO 2 is well established and has been found to enhance hydrogen photoproduction from alcohol-water mixtures by facilitating electron transfer and therefore inhibiting electron-hole recombination [6][7][8]. An alternative pathway recently proposed does not involve electron transfer to the metal but the recombination of the hydrogen atoms on the metal (reverse hydrogen spillover) made via the reduction of protons on the surface of TiO 2 [9].…”