Few-Layered Phosphorene–Graphitic Carbon Nitride Nanoheterostructure as a Metal-Free Photocatalyst for Aerobic Oxidation of Benzyl Alcohol and Toluene

Abstract

Herein, we have, for the first time, fabricated a few-layered phosphorene (FLP) and few-layered carbon nitride (FLCN) nanoheterostructure as a metal-free and broad solar light-absorbing photocatalyst for highly selective conversion of primary C–H bond of toluene and benzyl alcohol to benzaldehyde in the presence of oxygen. The FLP–FLCN photocatalyst can effectively oxidize benzyl alcohol to benzaldehyde with superior selectivity (>99%) under the visible light irradiation conditions. Moreover, a conversion rate of 82.6 mmol/(g h) from toluene to benzaldehyde is achieved after 24 h of photoreaction. The fine structural analysis including synchrotron-based X-ray absorption near-edge structure and photoelectron spectroscopy and electrochemistry signifies that the enhanced photocatalytic activity of FLP–FLCN is mainly contributed from the synergistic electronic coupling at the FLP–FLCN interface. The photogenerated hole–electron pairs and superoxide anion radicals play a crucial role in facilitating the C–H oxidation reaction. In addition, the FLP–FLCN can be reused for at least five cycles to efficiently photocatalytic conversion of benzyl alcohol without obvious loss of photocatalytic activity and microstructures. These findings provide a novel strategy to synthesize a metal-free nanocatalyst for the visible-light-driven photocatalytic conversion of specific organic transformation with high selectivity and superior conversion rate.

Graphene Oxide Supported Cubic ZnO for Enhanced Photodecomposition of Dyes

“…OH, and . O 2− , respectively [47,48] . As shown in Figure 9, it can be found that the degradation efficiency of ZnO‐GO‐1 decreases with the addition of capture agent and the photocatalytic efficiency decreased from 98.93 % (100 min) to 44.23 % (100 min), 50.12 % (100 min), and 52.67 % (100 min) in the presence of IPA, KI, and N 2 , respectively.…”

“…1 mmol KI, 1 mmol IPA and N 2 were added into the MO solution as the scavengers of the h + , * OH, and * O 2À , respectively. [47,48] As shown in Figure 9, it can be found that the degradation efficiency of ZnO-GO-1 decreases with the addition of capture agent and the photocatalytic efficiency decreased from 98.93 % (100 min) to 44.23 % (100 min), 50.12 % (100 min), and 52.67 % (100 min) in the presence of IPA, KI, and N 2 , respectively. The result of the catalytic degradation shows that * OH, h + , and * O 2À play the important role in the process of degrading MO and ZnO-GO-1 can generate more * OH to photocatalytic degrade dyes.…”

Visible Light-Induced Aerobic Oxidative Dehydrogenation of C–N/C–O to C=N/C=O Bonds Using Metal-Free Photocatalysts: Recent Developments

“…Several graphitic carbon nitrides were also employed as photocatalysts in the transformation of alcohols to aldehydes or ketones. Thus, a carbon-nanodot-doped material derived from 33 [193], a few-layered phosphorene nanostructure graphitic material [194], the basic unmodified graphitic carbon nitride 33 [119,195,196] and several 33 modified by thermal, chemical and mechanical processes [197], with N vacancies [198] and doped with P [199], O [200] and S atoms [201], could successfully catalyze the mentioned reaction under visible light irradiation. The photocatalysts were able to be reused after centrifugation or filtration without decreasing their catalytical activity.…”

Visible-light Responsive Cu-MOF-NH 2 for Highly Efficient Aerobic Photocatalytic Oxidation of Benzyl Alcohol

“…Alkoxide radicals are produced from alkoxide anions when they come into contact with a photogenerated hole. Then, the alkoxide reacts with another • O 2− and hole, releasing another proton from the hydroxymethyl moiety and forming a carbon radical [54].…”