Hydrothermal Method Research Articles

Synthesis of amorphous nickel-cobalt hydroxides for Ni-Zn rechargeable aqueous battery.

In this work we developed a hydrothermal method for synthesizing amorphous Ni-Co hydroxide (NC(OH)) and in the subsequent step crystalline NiCo2O4 (NCO) has been produced using water as the solvent. For nickel-zinc batteries, NC(OH) was found to have superior performance to its NCO prepared by two-step process.The XRD pattern showed mixed phases containing both Ni and Co hydroxides (during the initial step) and in the subsequent step (calcined) the formation of cubic spinel structure was noticed. For NC(OH), aggregated particles with irregular morphology were observed while clustered nanorod-like shapes were noticed for NCO samples. The nanorod morphology was obtained through a facile approach without employing any structure-directing agent. Both NC(OH) and NCO were employed as cathodes for Ni-Zn battery studies against Zn foil anode with a polyamide-based separator soaked in 6M KOH saturated with ZnO additive was used as electrolyte.The NC(OH) had a capacity of 268 mAhg-1 against 120 mAhg-1 for NCO at a current density of 1 Ag-1.The Ni-Zn battery presents energy and power densities of 428.8 WhKg-1 and 2.68 kWKg-1, respectively surpassing the normal values reported for aqueous rechargeable batteries.This work provides a facile approachfor developing bimetallic hydroxides for optimal energy storage performance.

Modified photoelectric performance by bandgap engineering in Al-doped α-Ga2O3 nanorod arrays

α-Ga2O3 has been attracted a focus of attention in ultraviolet detector applications due to its wide bandgap and cost-effective synthesis technology. This work presents Al-doped α-Ga2O3 nanorod arrays (AG-NRAs) synthesized by a facile hydrothermal method. The optical and photoelectric properties were systematically investigated. By adjusting Al-doping level, the bandgap can be regulated within a certain range from 4.39 to 4.78 eV. Solar blind UV photoresponse relied on the bandgap has been also studied by direct photocurrent measurements using a sandwich-structured FTO/AG-NRAs/FTO photoelectric device. The highest photocurrent density of 44.1pA/cm2 has been achieved in the specimen with Al-doping ratio of 0.15 with a rapid response time of 0.25 s. This finding offers an in-depth vision for bandgap engineering in AG-NRAs, and alternative approach for fabricating solar-blind UV detector.

Synthesis of Ag Doped ZnO Nanowire by Hydrothermal Method and its Characterization

This research is mainly focused over synthesizing zinc oxide (ZnO) nanowire (NW) and silver doped zinc oxide nanowires (Ag/ZnO) using two step hydrothermal method which comprises of seed layer deposition and hydrothermal nanowire growth step. Hydrothermally grown nanowires are of great significance. The synthesized nanowires were characterized by UV-Vis Spectroscopy (UV-Vis), X- ray Diffraction Spectroscopy (XRD), Energy Dispersive Spectroscopy (EDS), Field Emission Scanning Electron Microscopy (FE-SEM) and High-Resolution Transmission Electron Spectroscopy (HR-TEM). XRD pattern revealed as-synthesized materials are of crystalline nature having crystallite size of 166.27 nm and 42.32 nm for ZnO nanowire and Ag doped nanowire, respectively. Further confirmation was done by EDS, SEM and TEM. The microscopic images of SEM and TEM evidenced for successful fabrication of nanowires.

Rational Fabrication of MoS2/g‐C3N4 Heterostructures for Efficient Photocatalytic Degradation of Rhodamine B

AbstractMolybdenum disulfide (MoS2) and graphitic carbon nitride (g‐C3N4) heterojunctions were prepared through the hydrothermal method and the calcination method (namely, MoS2/g‐C3N4‐1 and MoS2/g‐C3N4‐2) for the photocatalytic degradation of Rhodamine B. X‐ray diffraction and scanning electron microscopy confirmed the formation of a heterostructure composite between MoS2 and g‐C3N4. The bandgap of MoS2 and g‐C3N4 was studied with ultraviolet–visible diffuse reflection spectroscopy and electrochemical Mott‐Schottky tests. MoS2/g‐C3N4‐1 exhibits remarkable efficiency in degrading Rhodamine B, achieving 91.2 % degradation in 1 h, which is 1.06 times higher than MoS2/g‐C3N4‐2. Additionally, the MoS2/g‐C3N4‐1 heterojunction demonstrates good reusability, maintaining a degradation efficiency of 71.2 % after 5 cycles. The reason lies in that the MoS2/g‐C3N4‐1 possesses a larger specific surface area (33.078 m2g−1) than MoS2/g‐C3N4‐2 (28.621 m2g−1). Free radical quenching experiments indicate that ⋅O2− serves as the primary active species for photocatalytic degradation. The findings indicate that incorporating g‐C3N4 into MoS2 improves its photocatalytic capability due to aligned energy bands, promoting charge transfer, and reducing electron‐hole recombination.

Harnessing the Power of Nano‐Ferroelectrics: BaTiO3/MXene (Ti3C2Tx) Composites for Enhanced Lithium Storage

Abstract2D Ti3C2Tx MXene is a desirable electrode material for advanced lithium‐ion batteries (LIBs) in the pursuit of high energy and power densities, owing to its extensive reactive area and surface‐induced pseudo‐capacitance. Here, a novel synergistic strategy for fortifying lithium storage capability is first proposed, by in‐situ anchoring BaTiO3 ferroelectric nanoparticles on few‐layered Ti3C2Tx nanosheets (BT/f‐Ti3C2Tx) using a hydrothermal method. The uniform BaTiO3 nanoparticles effectively prevent the restacking of Ti3C2Tx nanosheets, successfully deplete metastable Ti atoms, and intriguingly form a thin and well‐adhered solid electrolyte interface layer, enhancing the aggregation‐resistant, oxidation‐resistant, and electrochemical properties of Ti3C2Tx. Simultaneously, the internal electric fields, originating from the spontaneous polarization of BaTiO3 ferroelectric nanoparticles, can augment the adsorption of Li+, boosting the lithium storage capacity and reaction kinetics. The resulting composite electrode displays a remarkable charge capacity of 84 mAh g−1 at 10 A g−1, almost five times that of pristine Ti3C2Tx electrode. The excellent rate performance and cyclability make BT/f‐Ti3C2Tx composites highly attractive for LIBs. Furthermore, this synthetic approach presented here is scalable and can be extended to other Ti‐based materials. This strategy is expected to underscore the considerable potential of ferroelectric composites for integration into high‐performance LIBs.

Fluorescent Sensors Based on Lanthanide-Based Metal-Organic Frameworks via Devices and pH Response.

In light of the escalating industrial and environmental pollution, there is a pressing need for the development of novel materials capable of swiftly detecting pollutants. Here, we report the synthesis of five lanthanide metal-organic frameworks sharing a common structure, prepared via a hydrothermal method and denoted as [Ln2(H2DHBDC)2(phen)(H2O)6]n (where CUST-888 corresponds to Tb, CUST-889 corresponds to Eu, CUST-890 corresponds to Gd, CUST-891 corresponds to Dy, and CUST-892 corresponds to Nd). Notably, CUST-888 and CUST-889 exhibit discernible visual alterations in response to acidic and alkaline conditions. To assess their practical utility, luminescent test strips and light-emitting diode lights based on CUST-888 and CUST-889 were devised, enabling the visual detection of luminescence color changes induced by Hg2+, Cr2O72-, tetracycline, and 2,4,6-trinitrophenol. Furthermore, highlighters derived from CUST-888 and CUST-889 were designed, showcasing robust stability, adjustable color, and substantial potential for application in the realm of anticounterfeiting.

Synergizing ruthenium oxide with bimetallic Co2CrO4 for highly efficient oxygen evolution reaction

Designing efficient and stable oxygen evolution reaction (OER) catalyst is the basis for the development of sustainable electrolytic water energy techniques. In this work, we presented a heterogeneous-structured electrocatalyst composed of bimetallic oxides-modified RuO2 nanosheets supported on nikel foam (Co2CrO4/RuO2) using a hybrid hydrothermal, ion-exchange and calcination method. The unique synergy and interfacial coupling between Co2CrO4/RuO2 heterostructures are favorable for optimizing the electronic configuration at this interface and strengthening the charge transport capacity, thus strengthening the catalytic activity of the Co2CrO4/RuO2 catalyst. The experimental data demonstrate that Cr leaching facilitates the rapid reconstruction of the catalyst into oxyhydroxides (CoOOH), which are acknowledged to be the real active species of OER. Theoretical calculations show that the Co2CrO4/RuO2 heterostructure increases the density state at the Fermi energy level and lowers the d-band center, thereby strengthening the catalytic activity. The synthesized Co2CrO4/RuO2 catalyst exhibited OER performance with an overpotential of 209 mV at 10 mA cm−2 and displayed a low Tafel slope of 78.2 mV dec-1, which outperforms most reported advanced alkaline OER catalysts. This work contributes to a new tactic for the design and development of ruthenium oxide/bimetallic oxides electrocatalysts.

Adsorption characteristics and mechanisms of bisphenol A on novel nitrogen-modified biochar derived from waste masks and biomass.

Resource utilization of waste masks has become an urgent scientific issue. In this work, with sustainably, waste masks and biomass were co-pyrolysis with oxygen limitation to prepare mask-based biochar (MB). Then, urea was introduced to prepare novel nitrogen modified mask-based biochar (NMB) via a one-step hydrothermal synthesis method. The adsorption characteristics of NMB on the emerging environmental pollutant, bisphenol A (BPA), were evaluated via batch adsorption tests. Moreover, the physicochemical properties of the materials were characterized with various advanced techniques. Also, the roles of waste masks and nitrogen modification were explored. The adsorption mechanisms of NMB on BPA were revealed as well as the performance differences between different adsorbents. The results showed that waste masks participated in thermochemical reactions, shaped the microsphere structure of biochar, and increased the types of surface functional groups. The nitrogen modification enriched the surface elemental composition and activated the specific surface area via the mesopore. These would enhance the adsorption performance. The maximum adsorption of BPA by NMB was 62.63mg·g-1, which was approximately 2.35-5.58 times higher than that of the control materials. Temkin model and pseudo-second-order model optimally simulate the isothermal and kinetic adsorption, respectively. The adsorption mechanisms are jointly by physical and chemical adsorption, which mainly includes π-π interaction, hydrogen bonding, intraparticle diffusion, surface adsorption, and ion exchange. After discussion and evaluation, NMB has lower preparation process cost (7.21 USD·kg-1) and safety, with potential for environmental applications. This study aims to expand new ideas for the comprehensive utilization of waste masks and the preparation of eco-friendly materials. Moreover, it provides a theoretical basis for the removal of BPA.

In-situ interconnected 1D/2D/3D architectures of CNT/MoS2/Fe3O4 membranes for increasing degradation efficiency of penetrative electro-Fenton under low energy consumption

The electro-Fenton oxidation process for the degradation of organic pollutants in recalcitrant wastewater has garnered significant attention and research efforts in the field of advanced water treatment. This is primarily due to its highly effective degradation capabilities and the advantages it offers, including the avoidance of unsafe transportation and storage of hydrogen peroxide (H2O2). However, challenges such as relatively high energy consumption, complex operational requirements, and limited operational stability continue to pose significant economic constraints on the widespread application of electro-Fenton technology in water purification. In this study, we employed a secondary hydrothermal method to construct a multi-layered CNT/MoS2/Fe3O4 composite heterostructure in situ. Leveraging the synergistic effects of the introduced variable valence elements, Fe and Mo, and the interconnected multi-layered membrane structure, the CNT/MoS2/Fe3O4 electro-Fenton membrane holds promise in a permeable filtration system. Under the conditions of a current density of 1.50 mA/cm² and an electrolyte concentration of 0.50 mol/L, the CNT/MoS2/Fe3O4 composite membrane exhibited a degradation efficiency of over 90.00 % for 100.00 mg/L RhB within 10 minutes, and the degradation rate approached nearly 99.00 % at 60 minutes. Furthermore, the degradation efficiency for various recalcitrant organic dye wastewaters, including phenol, methyl orange, and methylene blue, could be maintained at levels ranging from 80.00 % to 97.00 %. Particularly, under optimized operating conditions, the specific energy consumption (EC) for the CNT/MoS2/Fe3O4 membrane process was measured at 0.60±0.01 kWh/m³, showcasing exceptionally low energy consumption characteristics. In conclusion, it is expected to contribute to the reduction of the overall consumption of heterogeneous electro-Fenton oxidation systems and enhance their operational efficiency. This innovative approach represents a significant advancement in the field, offering the potential to address the economic limitations associated with electro-Fenton technology in water quality purification.

Ultra-thin SnS2 nanosheets grown on carbon nanofibers with high-performance in sodium-ion energy storage

SnS2 with two-dimensional layered structure has great application promising in the energy storage system due to its super high theoretical capacity. However, the serious volume expansion and low intrinsic conductivity are difficult to meet the commercial application of SnS2 in sodium-ion batteries (SIBs). Herein, SnS2/CNF was successfully prepared by simple electrospinning technique and hydrothermal method. Based on the synergistic effect between ultra-thin nanosheets and carbon nanofibers (CNF), the anode material not only shortened the path of electron transport, but also accelerated the sodium ion reaction kinetics, thus showed outstanding stability and reversibility SIBs. The SnS2/CNF displayed the excellent rate properties (352 mAh g-1 at 5 A g-1) as well as stable long term cycle performance (338 mAh g-1 at 3 A g-1 after 500 cycles). Furthermore, the SnS2/CNF//AC sodium-ion hybrid capacitor (SIHCs) exhibits excellent energy density and power density of 97 Wh kg-1/54 W kg-1. The capacity retention is 81 % after 2500 cycles at 1 A g-1. The SIHCs could light up to 100 LEDs easily, which thus exhibited great practical application potential in energy storage device.

Comparative microstructural analysis of V2O5 nanoparticles via x-ray diffraction (XRD) technique

Vanadium pentoxide (V2O5) nanoparticles exhibit diverse properties and have been studied for a wide range of applications, including energy storage, catalysis, environmental remediation, and material enhancement. In this work, we have reported the synthesis of vanadium pentaoxide (V2O5) nanoparticles using hydrothermal method. Ammonium metavanadate (NH4VO3) was used as a source of vanadium. These syntheses were carried out at four different concentrations of vanadium source. The hydrothermal reaction was conducted at a temperature of 180 °C for a duration of 24 hours, followed by an additional 24 hours period of natural cooling. Four samples were annealed in air using a muffle furnace at 500 °C for five hours. The x-ray diffraction technique was used to study the structural aspects. A comparative analysis of the microstructure was conducted utilizing the Scherrer method, the Williamson–Hall method and its various models, size-strain analysis, and the Halder–Wagner method. The crystallite size and microstrain were determined using these distinct methods, revealing a systematic correlation between the crystallite size and microstrain obtained through the different techniques.

Comparative Study of Porous High‐entropy Oxides as Low‐temperature Catalysts for CO2 Methanation

High‐entropy oxides (HEOs) are an emerging class of materials whose compositional complexity has garnered attention because of their tailorable chemistries and unique properties arising from extreme configurational entropy. Solid‐state methods are often employed to synthesize HEOs, but such methods result in poor material properties for catalytic processes, leaving HEOs less studied for catalysis. Here we utilize different wet‐synthesis strategies to produce porous HEOs and investigate their performance in heterogeneous CO2 hydrogenation to methane. Specifically, HEOs were synthesized using hydrothermal, co‐precipitation, and solvothermal methods, resulting in different morphologies like platelets or spheres. Of the tested materials, HEOs with 2‐D platelets derived from hydrothermally‐synthesized high‐entropy layered double hydroxides had superior catalytic performance, especially in low‐temperature regimes (<300°C). K‐edge XANES indicated that metallic sites (Ni0‐Co0) were formed during the reaction, and these metallic sites are dispersed into the HEO matrix which is confirmed by STEM/elemental mapping. This facile synthesis approach allows for realized synergy between the metallic sites and the HEO support, leading to superior performance for CO2 methanation compared to low‐entropy counterparts. Finally, this study illustrates how HEOs offer new avenues of tailorability in terms of the interplay between support, active site and reaction temperatures for heterogeneous catalysis.

Strain-Induced Photocatalytic H2 Production over BiVO4 in Pure Water without Any Cocatalyst.

In this study, BiVO4 nanosheets (BiVO4-NS) were prepared by a facile hydrothermal method. It is found that sonication-induced strain can effectively promote the H2 production over BiVO4-NS in the presence of pure water without any cocatalysts. With the assistance of the sonication, the H2 production over BiVO4-NS is 1.344 mmol·g-1 after 3 h simulated sunlight irradiation, which is 24.8 times higher than that of BiVO4-NS without sonication (0.054 mmol·g-1). In addition, the products of water oxidation are determined to be hydroxyl radicals and hydrogen peroxide. Moreover, BiVO4-NS also shows obviously enhanced photoactivity than that of the commercially available BiVO4 nanoparticles (BiVO4-C). The improved photoactivity of BiVO4-NS is attributed to the effective charge separation and low charge transfer resistance. The underlying mechanism of sonication-promoted water splitting is investigated by a variety of controlled experiments. The results show that ultrasonic waves can produce obvious strain inside the sample, which results in lattice distortion of BiVO4. Therefore, the conduction band of BiVO4 is obviously negative shifted, which is beneficial for H2 production. In addition, the strain in BiVO4 also produces local polarization of the sample, which effectively promotes the charge transfer and separation process. It is hoped that our study could provide a new strategy for achieving efficient photocatalytic water splitting.

Constructing a Self-Supported Bifunctional Multiphase Heterostructure for Electrocatalytic Overall Water Splitting.

Developing well-performing and stable bifunctional electrocatalysts is of great importance for efficient green hydrogen production through water electrolysis. Herein, a three-dimensional self-supported CoMoS3.13/FeS2/Co3S4 on carbon paper (FeCoMoS/CP) heterostructure with interconnected nanosheets for overall water splitting was fabricated by a facile hydrothermal method followed by vulcanization treatment. The FeCoMoS/CP heterostructure with high structural integrity and more accessible active sites can effectively optimize the electronic structure through component regulation to achieve enhanced catalytic activity. Significantly, the FeCoMoS/CP required overpotentials of 257 mV at 50 mA cm-2 for OER and 280 mV at 20 mA cm-2 for HER. Importantly, the assembled FeCoMoS/CP||FeCoMoS/CP alkaline electrolyzer achieved a superior cell voltage of 1.48 V at 10 mA cm-2 with superb long-term stability, which implies a remarkable electrocatalytic performance of the FeCoMoS/CP heterostructure for overall water splitting. This work provides an applicable route for synthesizing high-performance bifunctional catalysts toward water electrolysis.

Cobalt Nanoparticles Supported Active Carbon from Chitosan Biopolymer Using Thermal Method: Synthesis, Characterization, and Hydrogen Production

AbstractActivated carbon based Cobalt nanoparticles (Co@AC NPs), considered in the context of hydrogen energy, which is a renewable and sustainable energy, were synthesized by the hydrothermal method, and their catalytic activities were tested. For this, hydrogen production tests were carried out with the help of sodium borohydride (NaBH4) methanolysis of Co@AC NPs synthesized by the thermal method. Ultraviolet–visible spectroscopy (UV–Vis), Fourier transmission spectroscopy (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD) characterization tests were performed. According to the TEM characterization result, it has been observed that the NPs have a spherical shape and an average size of 2.52 ± 0.92 nm. Then, using the catalytic studies, it was observed that hydrogen production’s reusability is found to be 86% . The activation energy (Ea), enthalpy (∆H), and entropy (∆S) values were found to be 20.28 kJ⋅mol−1, 17.74 kJ⋅mol−1, and −125.97 J⋅mol−1 K−1, respectively. The obtained values have yielded excellent results and guide future sustainable and renewable hydrogen energy studies by reducing costs, ensuring environmental sustainability by avoiding the formation of undesirable by-products, and producing hydrogen from NaBH4 through its high catalytic properties.

Eco-friendly synthesis of magnetic zeolite A from red mud and coal gasification slag for the removal of Pb2+ and Cu2+

The issue of heavy metal pollutants has gained global attention, while the disposal of industrial wastes remains a critical environmental concern that requires urgent treatment. In this study, the successful synthesis of magnetic zeolite A (MZA) aimed at the Pb2+ and Cu2+ removal was accomplished by capitalizing on the synergetic interplay between the red mud (RM) and coal gasification slag (CGS) compositions. A reduction roasting reaction involving iron and carbon was innovatively integrated into the conventional alkali fusion-activation process of silicon-aluminum components. The physicochemical properties and preparation mechanism of MZA were characterized using various analytical techniques. Adsorption isotherms and kinetics were analyzed employing various well-known models, and the reusability of MZA was investigated. The result showed that hematite in RM was converted into magnetite and metallic iron during the alkali fusion-synchronous reduction roasting process, and the aluminosilicates from RM and CGS were transformed into zeolite A through a hydrothermal method. The Langmuir and pseudo-second order models well described the Pb2+ adsorption behavior, while the adsorption process of Cu2+ followed the Freundlich and Elovich models best. These results confirmed the successful synthesis of MZA with excellent adsorption performance and magnetic properties, thereby demonstrating the potential of RM and CGS in heavy metal removal through resource utilization.

High photocatalytic activity of g-C3N4/CdZnS/MoS2 heterojunction for hydrogen production

In an effort to improve the light absorption efficiency of the photocatalyst, g-C3N4 nanosheets with visible light response have been prepared by roasting method, and the g-C3N4/CdZnS composite catalyst with 2D/0D architecture has been prepared by hydrothermal method after ultrasonic thinning. The g-C3N4/CdZnS/MoS2 composite catalyst with 2D/0D architecture has been synthesized by secondary hydrothermal method. TEM analysis proves that a close heterogeneous interface has been formed between g-C3N4 and CdZnS, and between CdZnS and MoS2. The ultraviolet diffuse reflectance spectrum shows that MoS2 has a wide light absorption range, which effectively enhances the light utilization ratio of the composite catalyst. The energy band structure diagram and photoelectrochemical test results show that a continuous stepped type II ternary heterojunction is formed among g-C3N4, CdZnS and MoS2, which promotes its separation of photogenerated charges. When the loading mass fraction of g-C3N4 and MoS2 is 4%, the hydrogen evolution rate of g-C3N4/CdZnS/MoS2 composite catalyst is 57.02 mmol g−1 h−1 under visible light, which is exceeding 20% that of g-C3N4/CdZnS and 4.79 times and 44.9 times higher than that of CdZnS and g-C3N4, respectively. The two-dimensional structure of g-C3N4 and MoS2 significantly improves the stability of the composite catalyst. This work offers feasible ways for ternary heterogeneous photocatalyst construction.

Study on Fe-doped BiOBr with enhanced visible photocatalytic activity for the degradation of levofloxacin

In this study, Fe-doped BiOBr photocatalysts were prepared by hydrothermal method. Due to the unique flower-like structure of the composite materials, when the Fe-ions doping amount was 3 mol%, the degradation rate of levofloxacin was 85.06 % within 30 min. After 5 cycles, the degradation rate of Fe-BiOBr could still reach 83.46 %, it exhibited good photocatalytic activity. In addition, the possible degradation products and pathways were predicted by LC–MS, and toxicity analysis of intermediates was carried out. In addition, the free radical capture experiments and electron paramagnetic resonance (EPR) revealed that h+, ∙OH and ∙O2- were the main reactive species, which in turn suggested the possible photocatalytic mechanism for the Fe-doped BiOBr system.

Two new transition CdII and MnII-based MOFs for highly effective photodegradation antibiotics

Two coordination polymers (CPs), [Cd3(L)3(phen)2]n (1) and [Mn(L)(phen)]n (2), [H3L=3,3′-(1,4-phenylenebis(methylenoxy)dibezoic acid] were synthesized via hydrothermal method. 1 features a 2D layered structure with the potential for 3D network formation through weak interactions, 2 exhibits a 1D waved chain capable of forming 3D polymeric chains via intra- or intermolecular hydrogen bonding (OH···O) interactions. Both CPs demonstrate promising photocatalytic activity against antibiotics, including chloramphenicol (CAP), metronidazole (MDZ), nitrofurazone (NFZ), oxytetracycline (OXY), and sulfamethazine (SMZ). Notably, CP 1 shows superior photocatalytic activity for NFZ degradation. Systematic investigations revealed that under optimized conditions, CP 1 achieves a remarkable ∼ 92.21 % photodegradation of NFZ at a concentration of 40 ppm NFZ with a photocatalyst dosage of 25 mg/L within 50 min. Radical quencher experiments identified h+ (positive holes) and O2•- as the primary active species driving the photodegradation process. Additionally, CP 1 maintained consistent performance over five cycles, indicating its stability and reusability for NFZ degradation.

Hydrothermal synthesis of carbon quantum dots from Citrus limetta peels: Exploration of pH sensing, non-hemolytic activity and thermoluminescent properties

This study introduces a novel hydrothermal green method for synthesized carbon quantum dots (CQDs) using dried powders of Citrus limetta peels as a carbon source. The synthesized CQDs were evaluated for their photothermal response, pH sensing under various conditions and biocompatibility through non-hemolytic activity. CQDs had low crystallinity and an average size of 3 nm, ranging from 1 to 6 nm. CQDs have biocompatible properties, which makes them suitable for developing pH sensors. The study also revealed that the temperature of CQDs increases up to 37 °C under laser light irradiation of 808 nm, which might have potential applications in the biomedical field.