Ultrathin Graphitic Carbon Nitride Nanosheets as Efficient Catalysts for Degradation of Pollutants under Visible Light

Abstract

In this paper, ultrathin g‐C3N4 nanosheets (U‐CNs‐4) were prepared via short time sonication‐assisted exfoliation and solvothermal treatment method in ethylene glycol solvent. It was found that the obtained ultrathin g‐C3N4 nanosheets with a thickness of ranges from 4 to 5 nm, exhibited a higher specific surface area of 35.7 m2/g and larger electronic band structure (by 0.16 eV), enhanced photocurrent response and improved electron transport ability due to the quantum confinement effect. The photocatalytic activities have been proved by photocatalytic degradation Rhodamine B (RhB) and ciprofloxacin (CIP) under visible‐light irradiation. Results show that the U‐CNs‐4 exhibited obviously enhanced photocatalytic activity in comparison with other samples. The degradation efficiency of RhB was 4.4 times higher than that of the bulk g‐C3N4 (B‐CN). The enhanced photocatalytic activity was due to the more active sites, the enhanced oxidation ability and improved electron transport ability, which improving separation efficiency of photogenerated electron‐hole pairs. Finally, the possible for the enhancing photocatalytic mechanism was revealed based on the active species trapping and electron spin resonance (ESR) experiments.

Ultrathin Mesoporous Carbon Nitride Nanosheets Prepared Through a One‐Pot Approach towards Enhanced Photocatalytic Activity

“…In addition, according to the recent theoretical research, we note that ultrathin g-C 3 N 4 nanosheets exhibit unique electronic and optical properties. [49,50] For instance, the ultrathin structure enables to provide numerous ordered channels and more active sites for effective charge carriers transportation and storage, furthermore improving the photocatalytic activity of g-C 3 N 4 . [51] Furthermore, in various synthetic methods previously reported, liquid exfoliation [49] and thermal exfoliation [52] may be considered as ideal approaches to construct ultrathin g-C 3 N 4 nanosheets.…”

Enhancement of graphitic carbon nitride (g‐C3N4) assisted photodegradation of Rhodamine B under visible light

“…The kinetics of RhdB under 18 W LED Light photodegradation on the catalyst surface is described by first‐order equation [60] $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\rm L}{\rm n}\left({\rm C}/{\rm C}{\rm o}\right)=-{\rm \ }{\rm k}{\rm t}\ \hfill\cr}}$$$ …”

“…The kinetics of RhdB under 18 W LED Light photodegradation on the catalyst surface is described by first-order equation [60] Ln C=Co ð Þ ¼ À kt (7) Where k is the rate constant (min À 1 ), C 0 and C are starting and actual concentration at regular time interval t (min) of RhdB dye under 18 W LED light source vertically irradiated. In absence of g-C 3 N 4 , RhdB molecule shows slender decomposition reflects the existence of stable RhdB molecule in aqueous solution under 18 W LED Light source irradiated vertically.…”

Modification of graphite carbon nitride by adding an ultra-micro amount of triaminotriphenylamine for superior photocatalytic hydrogen evolution

“…[10][11][12][13] Nevertheless, the photocatalytic performance of unmodified g-C 3 N 4 is still limited by its high recombination rate of photogenerated electron-hole pairs, small specific surface area and narrow response range of visible light. 14,15 In order to improve its photocatalytic performance, a lot of effective methods have been developed, 16 such as elemental doping, [17][18][19][20][21][22][23] heterojunctions, [24][25][26][27][28][29][30][31][32] specific morphology construction [33][34][35] and acidification with concentrated acids. 36,37 In the past few years, supramolecular chemistry has attracted extensive attention.…”