Rare earth oxynitrides: promising visible-light-driven photocatalysts for water splitting

Abstract

Perovskite-type rare earth oxynitrides are promising visible-light-driven photocatalysts for water splitting.

Metal nitride-based nanostructures for electrochemical and photocatalytic hydrogen production

“…Li et al was further improved AQE to 17.3% at 400 nm through (Ga 1-x Zn x ) (N 1-x O x ) nanostructure with grain size of 6 nm [ 295 ]. Recently, there is a significant progress seen in tantalum and niobium-based perovskite oxynitride material which interestingly offers the bandgap in 1.5–2.5 eV range that will help achieve the water-splitting reaction in the wide visible light region [ 296 ].…”

Transition-metal (oxy)nitride photocatalysts for water splitting

“…6 As a result, the absorption edges of these (oxy)nitride materials are mostly extended to the visible-light range while band-edge potentials suitable for OWS are maintained. [7][8][9][10] For instance, with increasing N content, the absorption-edge wavelengths become longer: from ∼320 nm for Ta 2 O 5 to ∼500 nm for TaON and ∼600 nm for Ta 3 N 5 . Thermodynamically, all of these materials can evolve both H 2 and O 2 from an aqueous solution.…”

Quantitative Analysis of Degree of Nitridation of Ta2O5 to TaON Particles and their Photocatalytic Oxygen Evolution Properties

“…In particular, the water‐splitting reaction performed using oxynitride photocatalysts is a promising candidate for the mass production of green hydrogen. Oxynitrides are typically prepared by heating oxides at a high temperature under NH 3 flow; this is referred to as nitridation [7–9] . For example, the nitridation reactions of Ta 2 O 5 and Sr 2 Ta 2 O 7 are as follows (Equations 1 and 2: $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm Ta}{_{2}}{\rm O}{_{5}}+{\rm 2NH}{_{3}}\rightarrow {\rm 2TaON}+{\rm 3H}{_{2}}{\rm O}\hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm Sr}{_{2}}{\rm Ta}{_{2}}{\rm O}{_{7}}+{\rm 2NH}{_{3}}\rightarrow {\rm 2SrTaO}{_{2}}{\rm N}+{\rm 3H}{_{2}}{\rm O}\hfill\cr}}$$$ …”

“…Oxynitrides are typically prepared by heating oxides at a high temperature under NH 3 flow; this is referred to as nitridation. [7][8][9] For example, the nitridation reactions of Ta 2 O 5 and Sr 2 Ta 2 O 7 are as follows (Equations 1 and 2):…”