Synthesis and characterization of Pd-doped carbon dots (CDP) for the photocatalytic degradation of imidacloprid

In the present study, the application of sequential biological and photocatalytic process was evaluated as a feasible process for the degradation of imidacloprid (IMI) in soil. Photocatalysis was carried out as a post and pre-treatment to the biological process as Microbial Photocatalytic (MP) and Photocatalytic Microbial (PM), respectively, to enhance the degradation and mineralization of IMI in soil. By both the processes, there was an enhancement in the percentage degradation of IMI i.e 86.2% for PM and 94.6% for MP process. The obtained results indicate that MP process is apparently more efficient in degradation of IMI which was observed with 15 days of biological treatment followed by 18 h of photocatalytic degradation (15 d + 18 h). The present work also reveals that though the difference in terms of the degradation of IMI after 5 d + 18 h, 10 d + 18 h & 15 d+ 18 h of MP process is not drastic, yet significant variation has been observed in terms of mineralization that truly signifies the removal of IMI from the soil. The LC analysis has shown that the intermediates formed during MP process are more and smaller in comparison to PM process, which further provides evidence that MP process is better than PM process for effective degradation of IMI in soil.

The composite of TiO2 and zeolite H-ZSM-5 has great photocatalytic ability for organic contaminants over a very large specific surface area and highlighted adsorption capacity. To describe abiotic degradation of imidacloprid, the photoinduced degradation of the pesticide imidacloprid in aqueous solutions, in the presence of TiO2 supported on H-ZSM-5 as photocatalyst, was performed. The study focused on the comparison of the imidacloprid degradation between photolysis and photocatalysis. The experimental results showed that the degradation of imidacloprid was more rapid in the condition of photocatalytic than that of photolysis or TiO2-only. The identification of possible intermediate products during the degradation was investigated by the high-performance liquid chromatography coupled with electrospray time-of-flight mass spectrometry (HPLC/TOF-MS). The main photocatalytic products were identified as chloronictinic acid, 1-[(6-chloro-3-pyridinyl) methyl]-2-imidazolidinone and 1-[(6-chloro-3-pyridinyl) methyl]-N-nitroso-2-imidazolidimine.

Self-assembly of tungstophosphoric acid/acidified carbon nitride hybrids with enhanced visible-light-driven photocatalytic activity for the degradation of imidacloprid and acetamiprid

Photocatalytic degradation of imidacloprid by composite catalysts H3PW12O40/La-TiO2

Hydrothermal synthesis of (m-t)BiVO4/g-C3N4 heterojunction for enhancement in photocatalytic degradation of imidacloprid

Novel ZnIn2S4/Co(acac)2: An inorganic-organic hybrid nanocomposite for enhanced removal of imidacloprid from aqueous phase

Environmental pollution has become an inexorable problem for the planet Earth. The precise detection and degradation of heavy metals, pesticides, industrial-, pharmaceutical- and personal care- products is needed. Nanotechnology holds great promise in addressing global issues. Over the past decades, nanozymic nanomaterials have exceptionally overcome the intrinsic limitations of natural enzymes. Carbon dots (CDs) exhibit unique structures, surface properties, high catalytic activities, and low toxicity. Different techniques, such as doping or surface passivation, can enhance these exceptional properties. Doping modifies CDs’ electronic, magnetic, optical, and catalytic properties considerably. Metal doping, a more significant strategy, involves the introduction of metallic impurities, which offer insight into enhancing the physicochemical properties of CDs. Metal-doped CDs exhibit higher optical absorbance and catalytic performance than pristine CDs. The literature shows that researchers have utilized various synthetic approaches to fabricate CDs-Metal nanozymes. Researchers have reported the metal-doped and hybrid CDs’ peroxidase, catalase, laccase, and superoxide dismutase-like activities. These metal-doped nanozymes put forward substantial environmental remediations and applications such as sensing, photocatalytic degradation, adsorption, and removal of environmental contaminants. This review thoroughly discussed the metal-based functionalization of CDs, the enzyme-like properties, and the ecological applications of metal-doped and hybrid enzymes. The review also presents the current novelties, remaining challenges, and future directions with key examples.

Prominent dual Z-scheme mechanism on phase junction WO3/CdS for enhanced visible-light-responsive photocatalytic performance on imidacloprid degradation

Gel-like carbon dots: A high-performance future photocatalyst

One-pot bioinspired synthesis of fluorescent metal chalcogenide and carbon quantum dots: Applications and potential biotoxicity

Enhanced photocatalytic degradation of imidacloprid and RhB by the precursor derived Bi12.7Co0.3O19.35 under different pH value

BACKGROUNDThis research deals with the photocatalytic degradation of the neonicotinoid insecticide imidacloprid. The reaction was carried out using a flat‐plate photoreactor in recirculated batch mode over an immobilized layer of a nitrogen‐doped TiO2 photocatalyst. The characterization of the prepared photocatalyst was performed using various instrumental techniques. The irradiation sources used were UV 365 nm high‐power light‐emitting diodes (LEDs) with various powers (20 and 30 W) and irradiation intensities. The radiation intensities were changed by adjusting the voltage supplied to the UVA‐LED radiation source. Design of experiments was used to evaluate the influence of three selected variables, namely initial concentration of imidacloprid solution, pH and UVA‐LED irradiance, on the photodegradation efficiency.RESULTSDoping the photocatalyst with nitrogen using urea as the nitrogen source leads to a decrease in the bandgap, Eg, compared to the characteristic values obtained for a commercial unmodified TiO2‐P25 photocatalyst (2.92 ± 0.021 versus 3.38 ± 0.015 eV). Analysis of the results using the Design‐Expert software package showed that irradiance was the most significant factor in the process studied.CONCLUSIONSTreatment of TiO2 with urea is more efficient method of TiO2 modification than nitrogen plasma pretreatment which resulted in a smaller decrease in Eg. The statistical parameters of the model equation obtained from analysis of variance confirmed the satisfactory fit of the proposed reduced cubic model to the experimental data. The results of kinetic analysis showed that the photocatalytic degradation of imidacloprid can be described by pseudo‐first‐order kinetics. © 2022 Society of Chemical Industry (SCI).

Carbon dots (C-dots) were facilely fabricated via a hydrothermal method and fully characterized. Our study shows that the as-synthesized C-dots are nontoxic, negatively charged spherical particles (average diameter 4.7 nm) with excellent water dispersion ability. Furthermore, the C-dots have a rich presence of surface functionalities such as hydroxyls and carboxyls as well as amines. The significance of the C-dots as highly efficient photocatalysts for rhodamine B (RhB) and methylene blue (MB) degradation was explored. The C-dots demonstrate excellent photocatalytic activity, achieving 100% of RhB and MB degradation within 170 min. The degradation rate constants for RhB and MB were 1.8 × 10−2 and 2.4 × 10−2 min−1, respectively. The photocatalytic degradation performances of the C-dots are comparable to those metal-based photocatalysts and generally better than previously reported C-dots photocatalysts. Collectively considering the excellent photocatalytic activity toward organic dye degradation, as well as the fact that they are facilely synthesized with no need of further doping, compositing, and tedious purification and separation, the C-dots fabricated in this work are demonstrated to be a promising alternative for pollutant degradation and environment protection.

A cost‐effective and green synthesis method was adopted for the synthesis of carbon dots (CDs) using easily available biomass, namely, Triticum (wheat), by varying the pyrolysis time. The synthesized CDs are labeled as A 1h, A 2h, and A 3h, respectively, where “A” represents the raw material, and “1h,” “2h,” and “3h” denote the respective pyrolysis time. XRD analysis reveals the turbostratic nature of the synthesized CDs. The size and shape of synthesized samples were visualized by HRTEM images. The bandgap was calculated by Tauc's plot and was determined to be 3.66, 5.08, and 4.89 eV for A 1h, A 2h, and A 3h, respectively. FTIR measurement analyzed the functional groups present on the surface of CDs. VSM measurement confirms the ferromagnetic behavior of CDs. Synthesized CDs have been used for photocatalytic degradation of rose bengal (RB) dye under UV light irradiation. Photocatalytic degradation increases with a decrease in bandgap and the maximum degradation efficiency (90.28%) was obtained for A 1h sample.

Investigation of visible-light-driven photocatalytic tetracycline degradation via carbon dots modified porous ZnSnO3 cubes: Mechanism and degradation pathway