Photoregenerable, Bifunctional Granules of Carbon-Doped g-C₃N₄ as Adsorptive Photocatalyst for the Efficient Removal of Tetracycline Antibiotic

Abstract

Environmental remediation employing semiconducting materials offer a greener solution for pollution control. Herein, we report the development of high surface area porous architecture of C3N4 nanosheets by a simple aqueous spray drying process. g-C3N4 nanosheets obtained by the thermal decomposition of urea-thiourea mixture are spray granulated to microspheres using 2 wt% poly vinyl alcohol (PVA) as binder. The post granulation thermal oxidation treatment resulted in in situ doping of carbon leading to improved photophysical properties compared to pristine g-C3N4. The C3N4 granules with surface area values of 150 m2/g rendered repetitive adsorption of tetracycline antibiotic (∼75% in 60 min) and the extended absorption in the visible region facilitated complete photocatalytic degradation upon sunlight irradiation (>95% in 90 min). The delocalized π bonds generated after carbon doping and the macro-meso porous architecture created by the granulation process aided high adsorption capacity (70 mg/g). The photoregenerable, bifunctional materials herein obtained can thus be employed for the adsorption and subsequent degradation of harmful organic pollutants without any secondary remediation processes.

Facile one-step synthesis of graphitic carbon nitride-modified biochar for the removal of reactive red 120 through adsorption and photocatalytic degradation

“…2c) slightly shifted, which were separated into three peaks centered at 284.8, 286.4 and 288.3 eV. These peaks can be assigned as graphitic sp 2 C-C or the cyano-group, surface amino functional group (C-NH 2 ) or C-O binding, and N-C=N coordination in the graphitic carbon nitride lattice, respectively (Panneri et al 2017). The high-resolution N1s spectra (Fig.…”

“…If it is self-regenerable, biochar can be used as an unlimited adsorbent because the adsorbed contaminant may be photocatalytically degraded under light irradiation. This provides fast regeneration of the biochar adsorbent and thus a promising novel solution for the removal of harmful contaminants (Panneri et al 2017). In previous studies, biochar has been modified with various photocatalysts such as Fe 3 O 4 , BiVO 4 , FeVO 4 , BiOCl and ZnO to remove contaminants through both adsorption and photocatalytic degradation (Jeon et al 2017;Kumar et al 2018;Li et al 2019;Xie et al 2019).…”

g-C3N4-Based Nanomaterials for Visible Light-Driven Photocatalysis

“…g-C 3 N 4 doping is a common strategy to broaden spectral utilization and band alignment to drive separate photogenerated charge carriers. Doping by metals such as Cu and Fe [224][225][226], non-metals such as B, C, O, or S [224,[227][228][229][230][231], and co-doping [232][233][234] have all been employed for environmental depollution applications. For example, S and O co-doped g-C 3 N 4 prepared by melamine polymerization and subsequent H 2 O 2 activation prior to trithiocyanuric acid functionalization (Figure 21a) enhanced the photocatalytic degradation of RhB (Figure 21b) 6-fold relative to the parent g-C 3 N 4 nanosheet [235].…”

Cost‐Efficient Graphitic Carbon Nitride as an Effective Photocatalyst for Antibiotic Degradation: An Insight into the Effects of Different Precursors and Coexisting Ions, and Photocatalytic Mechanism

“…However,b ecause of the quick recombination of the photoinduced electrons andh oles, the photocatalytic activity of commonly prepared g-C 3 N 4 is often relatively low in removal of antibiotic pollutants. To solve this drawback, the optimization of g-C 3 N 4 structure (morphologya nd copolymerization adjustment [14][15][16][17][18][19][20][21][22] )a nd introduction of "active component" (doping with an element, [23][24][25] heterostructure fabrication, [26][27][28][29][30] and modified by ac ocatalyst or plasma [31][32][33][34] )h aveb een considered as two common and effective strategies to realize the improvement in photocatalytic activity of g-C 3 N 4 .W hen in comparison with the structuraloptimizationofg-C 3 N 4 ,the strategy of introducing "active component" probably possesses the following severall imitations. Firstly,t he preparation method of such structure generally is extremely complicated, whichn ot only increases the cost butl argely restricts the large-scale application.…”