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Decoration of carbon dots over hydrogen peroxide treated graphitic carbon nitride: Exceptional photocatalytic performance in removal of different contaminants under visible light
摘要： The development of novel photocatalysts with considerable activity for completely removal of different pollutants from the environment is a dominating goal of modern chemistry. In this study, carbon dots (CDs) were adhered to the graphitic carbon nitride activated by hydrogen peroxide (ag-C3N4) to fabricate photocatalysts with exceptional ability upon visible-light illumination. Interestingly, the BET surface area, visible-light absorption characteristics, and electron-hole separation yield of the pristine g-C3N4 were improved after activation with H2O2 and decoration of CDs. The binary nanocomposite was used for degradation of MB, RhB, fuchsine, and phenol and photoreduction of Cr(VI) under visible light. The nanocomposite exhibited excellent photocatalytic performance with 100% removal of RhB in 60 min, which is almost 34.7 folds as premier as the pristine g-C3N4. Reactive species scavenging measurements displayed that ?O2?, ?OH, and h+ had significant roles for photodegradation of RhB. The possible mechanism was proposed regarding how activation with H2O2 and decoration of CDs improved the photocatalytic performance of g-C3N4. Also, stability of the composite was characterized through cyclic photocatalytic tests.
关键词： Graphitic carbon nitride,g-C3N4/CDs,Hydrogen peroxide treated g-C3N4,Visible-light-active photocatalyst
更新于2025-09-19 17:15:36
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A Review on Additives for Halide Perovskite Solar Cells
摘要： In this assay, a new polyethyleneimine-gold nanoparticles-protoporphyrin cobalt (II) (PEI-AuNPs-CoPP) nanocomposite was synthesized by a simple method under mild conditions, and it was used to fabricate an electrochemical sensor for the detection of hydrogen peroxide (H2O2). The structures of nanomaterials were characterized by fourier transform infrared (FTIR) spectroscopy and ultraviolet visible spectrometry (UV–vis). Under the optimum condition, the current intensity was linearly related to H2O2 concentration in the range of 50–280 aM (R2 = 0.9932). It's worth mentioning that a lower detection limit of 7.26 aM was obtained at a signal-to-noise rate of 3. In addition, the experiments showed that ascorbic acid (AA), uric acid (UA) and glucose (Glu) had little effect on the determination of H2O2. The sensor had a good analytical performance for the determination of H2O2 in human serum samples. These results suggested that the proposed PEI-AuNPs-CoPP nanocomposites had practical application prospect in biological sample analysis and clinical diagnosis.
关键词： Hydrogen peroxide sensor,Polyethyleneimine,Gold nanoparticle,Protoporphyrin cobalt (II)
更新于2025-09-19 17:13:59
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The study on saturation current and ideality factor of CdTe solar cell based on CdS window layer deposited with hydrogen peroxide
摘要： By adding hydrogen peroxide (H2O2) to the solution, a more compact cadmium sulfide (CdS) film with larger optical band gap is fabricated by chemical bath deposition method. The oxidation of CdS is confirmed by the formation of cadmium sulfate (CdSO4) in the CdS window layer via x-ray photoelectron spectroscopy investigation. The analysis of quantum efficiency considering the alloy CdS1?yTey shows that the oxygenated CdS suppress the S-Te interdiffusion, which promotes the spectral response in short-wave range. Moreover, this oxygenated CdS layer promoted the conversion efficiency of the cadmium telluride (CdTe) based solar cell from11.2% to 14.0% due to the improvement of open-circuit voltage and the fill factor. The transport mechanisms of saturation current are evaluated by temperature dependent current–voltage curves. Results show that the oxygenated window layer reduces both the interfacial and bulk recombination, thus improves the ideality factor. The decrease of bulk recombination in depletion region is attributed to the fewer trap level induced from S-Te interdiffusion. The decrease of interfacial recombination is attributed to the larger optical band gap of oxygenated CdS, which results in a spike-like conduction band alignment at CdS/CdTe heterojunction.
关键词： saturation current,CBD,open-circuit voltage,ideality factor,CdS:O/CdTe heterojunction,hydrogen peroxide
更新于2025-09-19 17:13:59
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Silver nanoparticles on graphene quantum dots as nanozyme for efficient H <sub/>2</sub> O <sub/>2</sub> reduction in a glucose biosensor
摘要： In this work, we developed graphene quantum dot-supported silver nanoparticles (AgNPs@GQDs) as Nanozyme for efficient electrocatalytic reduction of H2O2. We applied this composite material in a glucose oxidase-based glucose sensor, by drop casting a mixture of AgNPs@GQDs and chitosan (CS) on glassy carbon electrodes (GCE). Various conditions such as thickness of the AgNPs@GQDs/CS film, pH and temperatures were optimized. The proposed sensor presented excellent selectivity and sensitivity, a linear dependence on glucose concentration in the range 0.1–10 mM and a limit of detection of ca. 0.01 mM.
关键词： hydrogen peroxide reduction,electrochemical sensor,graphene quantum dots (GQDs),silver nanoparticles (AgNPs),glucose oxidase (GOx)
更新于2025-09-19 17:13:59
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Photo-physical studies of ultrasmall upconversion nanoparticles embedded organometallic complexes: Probing a dual mode optical sensor for hydrogen peroxide
摘要： Here, we report an upconversion nanoparticles (UCNPs) embedded organomettalic complex for detection of hydrogen peroxide (H2O2). The structural as well as the optical properties of the hybrid nanoparticles (HNPs) have been studies to confirm the interaction as well as energy transfer mechanism. The structural characterization confirm the weak interacting force between the UCNPs and the organic complex in HNPs. The optical studies reveal that, HNPs show characteristic optical behaviour of both the phases i.e. it gives an intense downconverted red emission under UV excitation, due to the presence of organic part (Eu3t ion) as well as an efficient blue upconverted emission from inorganic part (Tm3t ion) under NIR excitation. The energy transfer between the inorganic (Tm3t ion) and the organic (Eu3t ion) material has been observed, which confirms the effective attachment of both the phases in HNPs. The upconversion and downconversion emission properties, have been have successfully utilized for dual mode H2O2 detection.
关键词： Hydrogen peroxide sensor,Lanthanides,Hybrid nanoparticles,Energy transfer
更新于2025-09-19 17:13:59
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Evaluation of the color change and tooth sensitivity in treatments that associate LED Violet with carbamide peroxide 10%: a randomized clinical trial of a split-mouth design
摘要： Background: To evaluate the bleaching efficacy and post-operative sensitivity of 10% carbamide peroxide (PC) with or without violet LED (VL). Methods: Thirty patients were selected and were instructed to perform home bleaching treatment using PC 10%, for 8 hours daily, for 21 days. All patients underwent in-office irradiation of only one hemiarch with VL for 30 minutes, twice per week for three weeks, totaling six clinical sessions of irradiation. The treatment used for each hemiarch was determined randomly. The analyses were performed at the initial time and 7, 14, and 21 days after the start of treatment and 7 and 14 days after the end of the bleaching treatment. For color analysis, digital spectrophotometry was done using the Visual Analog Scale and cold detection was performed using the thermo-sensory analysis II (TSA II) equipment. The ANOVA-two way with repeated measures and the Tukey test (α=0.05) were used for the color and cold sensitivity analysis. Results: On analyzing the color change, it was observed that the hemiarch that was irradiated with VL presented the highest values compared with the side that did not receive irradiation. Regarding tooth sensitivity, there was no report of any patient experiencing discomfort during the bleaching protocol. Analysis of the dental thermal sensation threshold showed that the use of VL made the teeth more sensitive. Conclusions: It can be concluded that the VL provided a positive effect on color alteration when used in conjunction with 10% PC. However, the use of this new protocol made the teeth more sensitive.
关键词： Carbamide Peroxide,Hydrogen Peroxide,Dentin Sensitivity,Teeth Bleaching,Violet LED
更新于2025-09-16 10:30:52
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The synthesis of Co <sub/>x</sub> Ni <sub/>1?x</sub> Fe <sub/>2</sub> O <sub/>4</sub> /multi-walled carbon nanotube nanocomposites and their photocatalytic performance
摘要： A series of CoxNi1?xFe2O4/multi-walled carbon nanotube (CoxNi1?xFe2O4/MWCNTs) nanocomposites as photocatalysts were successfully synthesized, where CoxNi1?xFe2O4 was synthesized via a one-step hydrothermal approach. Simultaneously, methylene blue (MB) was used as the research object to investigate the catalytic effect of the catalyst in the presence of hydrogen peroxide (H2O2). The results showed that all the photocatalysts exhibited enhanced catalytic activity compared to pure ferrite. In addition, compared with the other photocatalysts, the reaction time was greatly shortened a significantly higher removal rate was achieved using 3-CNF/MWCNTs. There was no significant decrease in photodegradation efficiency after three catalytic cycles, suggesting that CoxNi1?xFe2O4/MWCNTs are recyclable photocatalysts for wastewater treatment. Our results indicate that the CoxNi1?xFe2O4/MWCNT composite can be effectively applied for the removal of organic pollutants as a novel photocatalyst.
关键词： methylene blue,photocatalysts,hydrothermal approach,wastewater treatment,multi-walled carbon nanotube,hydrogen peroxide,CoxNi1?xFe2O4
更新于2025-09-16 10:30:52
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Oral mucosal irritation potential of antimicrobial chemotherapy involving hydrogen peroxide photolysis with high-power laser irradiation for the treatment of periodontitis
摘要： In the present study, we assessed the oral mucosal irritation potential of antimicrobial chemotherapy involving hydrogen peroxide (H2O2) photolysis with a 405-nm laser device at an output power of ≥100 mW in hamsters. Twenty-four cheek pouches from 12 male Syrian hamsters received 7-min treatment with pure water (PW), 3% H2O2, laser irradiation of PW at 100 mW, laser irradiation of 3% H2O2 at 100 mW, laser irradiation of PW at 200 mW, or laser irradiation of 3% H2O2 at 200 mW (n = 4 each). The diameter of the irradiation area was set at 3 mm; accordingly, the calculated irradiances (optical power densities) of the 100- and 200-mW laser lights were approximately 1400 and 2800 mW/cm2, respectively. In addition, 12 cheek pouches from six animals received laser irradiation of 3% H2O2 at 100 mW for 1, 3, or 5 min (n = 4 each). Each treatment was repeated three times at 1-h intervals. Macroscopic and histological changes were evaluated 24 h after the last treatment. In addition, in vitro bactericidal activity of the treatment against periodontal pathogens was evaluated. We found that 405-nm laser irradiation of 3% H2O2 caused moderate to severe oral mucosal irritation when performed at powers of 100 and 200 mW for ≥3 min, while the same treatment performed at 100 mW for 1 min resulted in mild irritation. Moreover, 1-min H2O2 photolysis at 100 mW caused a >4-log decrease in viable bacterial counts. These findings suggest that 1-min H2O2 photolysis, which can effectively kill periodontal pathogens, may be acceptable when a 405-nm laser device is used at 100 mW. However, use of the laser at a lower power would be preferable for the prevention of unnecessary oral mucosal irritation.
关键词： hydroxyl radicals,photolysis,periodontitis,oral mucosal irritation,laser irradiation,antimicrobial chemotherapy,hydrogen peroxide
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS) - Seoul, Korea (South) (2019.1.27-2019.1.31)] 2019 IEEE 32nd International Conference on Micro Electro Mechanical Systems (MEMS) - Laser-Induced Graphene Stamp for High Performacne Elecrochemical Sensing Applications
摘要： Here, we newly proposed laser-induced graphene (LIG) stamp to transfer directly it onto Au substrate from polyimide (PI) substrate. The stamped-LIG was strongly adhered by van der waals force with Au. Unlike conventional transferred LIG electrode composed of totally carbon-based material, the proposed LIG stamp was formed with several layers of carbon on top of highly conductive Au electrode resulting in the improvement electrical and electrochemical properties. In addition, we successfully electrodeposited Pt nanoparticles (PtNPs) as catalytic material on the surface of the stamped LIG for electrochemical biosensor applications, which also resulted in highly improved redox characteristics. We characterized and compared various materials such as Au, Au/PtNPs, Au/stamped-LIG, and Au/stamped-LIG/PtNPs through cyclic voltammetry and amperometric measurement. As a result, the electrical and electrochemical redox properties were much improved. Through amperometric measurement, the developed electrochemical sensor electrode indicated 69.33 μA/mM·cm2 of the sensitivity at hydrogen peroxide concentration of 10 to 3760 μM and limit of detection of 2.2 μM, respectively.
关键词： Pt nanoparticles,electrochemical sensing,biosensor,hydrogen peroxide,laser-induced graphene
更新于2025-09-12 10:27:22
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Flexible electrochemical sensor based on laser scribed Graphene/Ag nanoparticles for non-enzymatic hydrogen peroxide detection
摘要： Here, we demonstrate the detection of H2O2 with a novel, ?exible and non-enzymatic electrochemical sensor based on a laser scribed graphene electrode decorated with silver nanoparticles(LSG-Ag). This low-cost technique based on a DVD laser, allowed the direct manufacturing and reduction of graphene oxide into an electrochemical transducer with conductive, lightweight, reduced and ?exible characteristics. The LSG-Ag sensor showed a high catalytic response towards H2O2 reduction at -0.5 V with a fast amperometric response of only 3 s. The sensor exhibited a wide linear range from 0.1 to 10 mM (R2 = 0.9982), a low LOD of 7.9 μM with high repeatability of 3% R.S.D. and reproducibility of 4.5% R.S.D. In addition, the LSG-Ag retained its operational characteristics after continuous bending with a loss of current of only 13%. Considering the need of progression of electrochemical systems into trending areas where ?exibility is required, the laser-induced sensors can provide a suitable platform for ?exible, reliable, sensitive and selective detection.
关键词： Flexible,Laser-induced,Hydrogen peroxide,Non-enzymatic,Graphene
更新于2025-09-12 10:27:22