Ni–Ti Layered Double Hydroxide@Graphitic Carbon Nitride Nanosheet: A Novel Nanocomposite with High and Ultrafast Sonophotocatalytic Performance for Degradation of Antibiotics

Abstract

Pollution of water resources by antibiotics is a growing environmental concern. In this work, nanocomposites of g-C 3 N 4 @Ni−Ti layered double hydroxides (g-C 3 N 4 @Ni− Ti LDH NCs) with high surface areas were synthesized through an optimized hydrothermal method, in the presence of NH 4 F. Application of various characterization techniques unraveled that the prepared nanocomposites are composed of porous Ni−Ti LDH nanoparticles and hierarchical g-C 3 N 4 nanosheets. Further, these NCs were employed for photocatalytic and sonophotocatalytic removal of amoxicillin (AMX), as a model antibiotic, from aqueous solutions. In addition, sonocatalysis was performed. It was found out that the g-C 3 N 4 @Ni−Ti LDH NCs outperform their pure g-C 3 N 4 and Ni−Ti LDH components in photocatalytic degradation of AMX under visible light irradiation. Also, the following order was determined for efficiency of the three adopted processes: sonocatalysis < photocatalysis < sonophotocatalysis. Furthermore, variation of the sonophotocatalysis conditions specified 500 W light intensity, 9 s on/1 s off ultrasound pulse modem and 1.25 g/L g-C 3 N 4 -20@Ni−Ti LDH as the optimal conditions. In this way, optimization of the highly efficient sonophotocatalytic process resulted in 99.5% AMX degradation within 75 min. Moreover, a TOC analyzer was employed to estimate the rate of AMX degradation over the nanocomposites. In addition, formation of hydroxyl radicals ( • OH) on the surface of the g-C 3 N 4 -20@Ni−Ti LDH particles was approved using the terephthalic acid probe in photoluminescence (PL) spectroscopy. No significant loss was observed in the sonophotocatalytic activity of the nanocomposites even after five consecutive runs. Also, a plausible mechanism was proposed for the sonophotocatalysis reaction. In general, our findings can be considered as a starting point for synthesis of other g-C 3 N 4 -based NCs and application of the resultant nanocomposites to environmental remediation.

Advanced Oxidation Processes for the Removal of Antibiotics from Water. An Overview

“…Also, Abazari et al [187] applied Ni−Ti layered double hydroxide@graphitic carbon nitride nanosheet for photocatalytic and sonophotocatalytic removal of amoxicillin from aqueous solution. The authors related the enhancement in the sonophotocatalytic activity of the nanocomposites to their higher specific surface areas, the intimacy of the contact interfaces of their components, the synergistic effect between these components, and the restriction of electron−hole recombination.…”

Ultrasonically Induced Sulfur-Doped Carbon Nitride/Cobalt Ferrite Nanocomposite for Efficient Sonocatalytic Removal of Organic Dyes

“…XPS analysis also reveals the atomic ratios of C, Co, Fe, O, N, and S of the SCN/CoFe2O4 nanocomposite to be 54.39%, 2.03%, 39.83%, 2.36%, and 0.94%, respectively. Figure 5c, arose from the C-S bond in SCN and S-O bond due to the surface adsorption of oxygen during the calcination process [27,28,30]. The Co 2p spectrum, depicted in Figure 5d, was attributed to the presence of Co 2+ cations.…”

“…Compared to the other catalyst materials, graphitic carbon nitride (g-C 3 N 4 ) has been broadly studied for its appealing lamellar structure, low-cost, non-toxic, high abundance, and recyclability. Because of its fast electron-hole recombination rate and relatively low specific surface area, g-C 3 N 4 is doped with metals or non-metal species such as Fe, Ag, Au, O, B, and P, coupling with TaON, Bi 2 WO 6 [11,19,[23][24][25][26][27][28]. Sulfur doped g-C 3 N 4 (SCN) effectively narrows down the bandgap with the enhancement of the catalytic activity.…”

“…The electronegativity of S is lower than that of N, which results in its unique electronic structure where the S-doped levels are located above the maximum valence band of doped g-C 3 N 4 . However until now, little attention has been focused on SCN to investigate the sonocatalytic degradation of organic dyes [26,28].…”

Recent Progress in Two‐Dimensional Layered Double Hydroxides and Their Derivatives for Supercapacitors

“…[12] In addition, M + and M 4 + ions can also be introduced to extendt he range of LDHs, such as LiAl LDH [13] and NiTiL DH. [14] There are several processing techniques that have been developed to synthesize LDHs for applications in SCs, such as hydrothermal, [15] electrodeposition, [16] chemical exfoliation and self-assembly, [17] and templating methods. [18] The LDHs thus-developedh aveb een studied for their performance as electrode materials in energy storage, in which they can offer the following advantages:1 )LDHs with al amellar structure and grown High-performance supercapacitors have attracted great attention due to their high power, fast charging/discharging, long lifetime, and high safety.H owever,t he generally low energy density and overall device performance of supercapacitors limit their applications.I nr ecent years, the design of rational electrode materials has provent ob ea ne ffective pathway to improvet he capacitive performances of supercapacitors.…”