Amine-Functionalized Crystalline Carbon Nanodots Decorated on Bi₂WO₆ Nanoplates as Solar Photocatalysts for Efficient Degradation of Tetracycline and Ciprofloxacin

Abstract

A bismuth tungstate (Bi 2 WO 6 ) nanoplate surface decorated with amine-functionalized crystalline carbon nanodots (ACCN) is developed as a sunlight responsive photocatalyst for degradation of tetracycline and ciprofloxacin antibiotics. The photocatalyst, named ACCN/Bi 2 WO 6 , has been thoroughly characterized to elucidate its structural, morphological, textural, and compositional aspects. The crystalline carbon nanodots are synthesized by hydrothermal treatment of ortho-phenylenediamine with a zwitterionic L-alanine, which offered doping of a large number of nitrogen atoms. Because of these features, compared to pristine Bi 2 WO 6 , the optimized batch of the photocatalyst prepared with 2 wt % ACCN (named 2-ACCN/Bi 2 WO 6 ) exhibited significantly enhanced degradation of tetracycline (96%) and ciprofloxacin (95%) within 75 min of sunlight exposure. The corresponding photocatalytic degradation rates are 0.030 and 0.027 min −1 , respectively. The mechanism involved in photocatalytic degradation is addressed in the light of ( a) enhanced absorption of sunlight by 2-ACCN/Bi 2 WO 6 , (b) favorable Z-scheme-like band positions of Bi 2 WO 6 and the HOMO−LUMO levels of ACCN, (c) large photocurrent density, (d) inhibition of charge carrier recombination and formation of reactive oxygen species (ROS), (e) in situ generation of a superoxide radical anion (O 2 −• ), confirmed by specific ROS scavenging studies, and (f) identification of intermediate products by ultraperformance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry.

Review On Strategies For the Design and Synthesis of Flower‐Like Bi2WO6 and BiOX (X=F, Cl, Br, I) Composites for Photocatalytic Environmental Remediation

“…Dutta et al, has doped the amine functionalized carbon dots over the Bi 2 WO 6 nanoplates which efficiently acts as a photocatalyst under the sunlight and employed for the degradation of the tetracycline and ciprofloxacin with 96 and 95 % degradation rate respectively. [121] Hoang and co-workers also used N-doped Bi 2 WO 6 nanoparticles were studied, as well as the effect of Ndoping quantity on photocatalytic activity. In comparison, the doped sample containing a N/Bi atomic ratio of 0.5 % had the optimum photodegradation performance for eliminating RhB when exposed to visible light.…”

“…Dopant with the non‐metals such as the N, C, S and oxides of the non‐metals helps to fabricate the desired optimum Bi‐based composite acting as a photocatalyst and enhances the photocatalytic degradation performance. Dutta et al, has doped the amine functionalized carbon dots over the Bi 2 WO 6 nanoplates which efficiently acts as a photocatalyst under the sunlight and employed for the degradation of the tetracycline and ciprofloxacin with 96 and 95 % degradation rate respectively [121] . Hoang and co‐workers also used N‐doped Bi 2 WO 6 nanoparticles were studied, as well as the effect of N‐doping quantity on photocatalytic activity.…”

Enabling N2 to Ammonia Conversion in Bi2WO6‐Based Materials: A New Avenue in Photocatalytic Applications

“…Apart from these, there are many more examples such as 2D/2D Bi 2 WO 6 /BiOI [14] for CO 2 reduction, Bi 2 WO 6 /TiO 2 [15] for CO 2 reduction (CH 4 production), 2D/2D Mxene/Bi 2 WO 6 [16] nanosheets for CH 4 /CH 3 OH production from CO 2 . Similarly, amine-functionalized C-dots /Bi 2 WO 6 [17] had been used for antibiotic (Tetracycline and Ciprofloxacin) degradation or g-C 3 N 4 /AgBr/Bi 2 WO 6 [18] materials system was used for inorganic pollutant (Tetracycline) degradation. Although research is still in progress in these areas with the scope for improvement, research is still an infant in the case of photocatalytic nitrogen fixation.…”