Comparative Studies of Oxygen‐Free Semiconductors in Photocatalytic CO₂ Reduction and Alcohol Degradation

Abstract

Commercially available a-SiC, b-SiC, GaN, ZnTe and self-synthesized g-C 3 N 4 were investigated in a comparative study regarding their photocatalytic capabilities in CO 2 reduction and alcohol degradation. Under reproducible high-purity solid-gas conditions none of the tested materials promoted CO 2 reduction using H 2 O as proton donor, although TiO 2 P25 has been shown to produce significant amounts of CH 4 under similar conditions. Replacing H 2 O with 2-propanol led to hydrocarbon formation which could solely be attributed to alcohol degradation while no CO 2 reduction took place.

Selectivity Control of CO2 Reduction over Pt/g-C3N4 Photocatalysts under Visible Light

“…The optical properties of the synthesized g-C 3 N 4 samples were studied using UV-Vis spectroscopy (Figure 1a). Absorption edges slightly decrease from 2.82 to 2.75 eV with the increase in calcination temperature (Figure 1b), which corresponds to the band gap of g-C 3 N 4 [28,32]. X-ray diffraction pattern (Figure S1) demonstrates a dominant peak at 2θ≈28 • , that is attributed to the (002) plane of g-C 3 N 4 [33].…”

Support‐induced structural changes in CO2 hydrogenation to higher alcohols over metal/oxide catalysts

“…is a hot topic in both scientific research and industrial applications. [2][3][4][5][6][7][8] Among these products, higher alcohols (HA) have higher energy density and lower vapor pressure as well as can be used as a viable alternative to methanol, both as a fuel and as a fuel additive. [9][10][11] In addition, it is an important chemical raw material for the synthesis of various chemicals, pharmaceuticals, detergents, cosmetics, and preservatives.…”

“…Therefore, the conversion of CO 2 to high‐value products (e. g., methanol, higher alcohols, light olefin, etc.) is a hot topic in both scientific research and industrial applications [2–8] . Among these products, higher alcohols (HA) have higher energy density and lower vapor pressure as well as can be used as a viable alternative to methanol, both as a fuel and as a fuel additive [9–11] .…”