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- 摘要
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- 实验方案
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Effective Fixation of Carbon in ga??C <sub/>3</sub> N <sub/>4</sub> Enabled by Mga??Induced Selective Reconstruction
摘要： The methodology of metal-involved preparation for carbon materials is favored by researchers and has attracted tremendous attention. Decoupling this process and the underlying mechanism in detail are highly required. Herein, the intrinsic mechanism of carbon fixation in graphitic carbon nitride (g-C3N4) via the magnesium-involved carbonization process is reported and clarified. Magnesium can induce the displacement reaction with the small carbon nitride molecule generated by the pyrolysis of g-C3N4, thus efficiently fixing the carbon onto the in situ template of Mg3N2 product to avoid the direct volatilization. As a result, the N-doped carbon nanosheet frameworks with interconnected porous structure and suitable N content are constructed by reconstruction of carbon and nitrogen species, which exhibit a comparable photoelectric conversion efficiency (8.59%) and electrocatalytic performances to that of Pt (8.40%) for dye-sensitized solar cells.
关键词： magnesium inducement,reconstruction mechanism,dye-sensitized solar cells,graphitic carbon nitride (g-C3N4),tri-iodide reduction
更新于2025-09-23 15:19:57
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Boosting Performance of Nona??Fullerene Organic Solar Cells by 2D ga??C <sub/>3</sub> N <sub/>4</sub> Doped PEDOT:PSS
摘要： The power-conversion efficiency (PCE) of single-junction organic solar cells (OSCs) has exceeded 16% thanks to the development of non-fullerene acceptor materials and morphological optimization of active layer. In addition, interfacial engineering always plays a crucial role in further improving the performance of OSCs based on a well-established active-layer system. Doping of graphitic carbon nitride (g-C3N4) into poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) as a hole transport layer (HTL) for PM6:Y6-based OSCs is reported, boosting the PCE to almost 16.4%. After being added into the PEDOT:PSS, the g-C3N4 as a Bronsted base can be protonated, weakening the shield effect of insulating PSS on conductive PEDOT, which enables exposures of more PEDOT chains on the surface of PEDOT:PSS core-shell structure, and thus increasing the conductivity. Therefore, at the interface between g-C3N4 doped HTL and PM6:Y6 layer, the charge transport is improved and the charge recombination is suppressed, leading to the increases of fill factor and short-circuit current density of devices. This work demonstrates that doping g-C3N4 into PEDOT:PSS is an efficient strategy to increase the conductivity of HTL, resulting in higher OSC performance.
关键词： hole-transport layers,PEDOT:PSS,organic solar cells,g-C3N4,non-fullerene acceptors
更新于2025-09-23 15:19:57
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Plasmonic enhanced photoelectrochemical aptasensor with D-A F8BT/g-C3N4 heterojunction and AuNPs on a 3D-printed device
摘要： D-A F8BT/g-C3N4 type II heterojunction nanocomposite was employed as photoelectrode material for photoelectrochemical (PEC) aptasensor based on rolling circle amplification (RCA) with the assistance of 3D-printed device for carcinoembryonic antigen (CEA) detection. D-A type F8BT improved photocurrent response of g-C3N4 nanosheet after forming D-A F8BT/g-C3N4 type II heterojunction which effectively constructed built-in electric field and reduced electron-hole recombination. With the introduction of DNA-AuNP probes by π-stacking interaction, the local plasmon resonance (LSPR) of AuNPs enhanced local electric field, promoted the generation of electron-hole and further improved photocurrent response. When target CEA was in presence of sensing platform, sandwich construction was formed between two kinds of CEA aptamers and CEA on magnetic beads, triggering the RCA reaction to produce repeated sequences. Partial sequences of complementary-DNA in combination with RCA results was digested by Exo III enzyme to release signal-DNA, detaching DNA-AuNP probes from the surface of the F8BT/g-C3N4 by complementation, causing the attenuation of LSPR and the decrease of photocurrent response. Combing with 3D-printed device, this PEC aptasensor exhibited a linear response to CEA from 0.02 ng mL?1 to 50 ng mL?1 with detection limit of 6.7 pg mL?1, contributing to develop all organic polymer semiconductors as photoelectric materials in PEC study.
关键词： Type II heterojunction,Rolling circle amplification,Photoelectrochemical aptasensor,D-A F8BT/g-C3N4 nanocomposites,3D-printed device,Local surface plasmon resonance
更新于2025-09-23 15:19:57
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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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Unraveling the impact of the Pd nanoparticle@BiVO <sub/>4</sub> /S-CN heterostructure on the photo-physical & opto-electronic properties for enhanced catalytic activity in water splitting and one-pot three-step tandem reaction
摘要： Pd nanoparticles embedded SBVCN-37 heterostructure photocatalyst is synthesized and employed in the water splitting reaction and for the synthesis of imines via one-pot tandem reaction involving photocatalytic reduction of nitrobenzene, oxidation of benzyl alcohol, followed by condensation reaction between them. Embedded Pd nanoparticles (mean diameter ~ 5-7 nm) act as an electron mediator and enhance the catalytic activity during oxidation and reduction reactions. Experimental results confirm that the light induced holes owing to its favourable redox potential oxidize N2H4 to N2 and liberate H+ ions that subsequently react with photogenerated electrons and facilitate the nitrobenzene reduction. The obtained quantum yield for benzyl alcohol oxidation and nitrobenzene reduction are calculated to be (2.08 %) and (6.53 %) at λ = 420 nm light illumination. The obtained apparent quantum yields for OER and HER are calculated to be 10.22 % and 12.72 % at 420 nm indicating the excellent potentiality of the presently investigated photocatalyst for solar fuel production. Photoelectrochemical (PEC) and time resolved & steady state photoluminescence measurements reveal that an optimum amount of Pd nanoparticles over SBVCN-37 is the crucial factor for achieving the highest photocurrent response, the lowest charge transfer resistance, and the efficient carrier’s mobility alteration leading to a prominent catalytic activity. Further, Mott-Schottky (M-S) analysis confirms that the deposition of Pd nanoparticles effectively reduces the over-potential and fine-tunes the band edge potential required for HER and OER reactions, independently.
关键词： Tandem Reaction,BiVO4,Benzyl Alcohol Oxidation,Apparent Quantum Yield,Nitrobenzene Reduction,g-C3N4,Photocatalytic H2 and O2 Production
更新于2025-09-19 17:15:36
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Effect of thermal condensation temperature on electrochemical capacitive properties of g-C3N4 supported on reduced TiO2 nanowires/nanotubes array
摘要： In this work, effect of processing temperature in electrochemical capacitors was investigated for g-C3N4. The g-C3N4 materials (CN) were synthesized by thermal condensation of melamine precursor at different temperature (450, 550 and 650 °C). Then, the g-C3N4 materials were deposited on electrochemically reduced TiO2 nanowires/nanotubes arrays (rTWTA)/Ti substrate. The g-C3N4/rTWTA/Ti electrodes were used as supercapacitor electrodes. Morphology, crystal structure and chemical composition of the g-C3N4/rTWTA/Ti electrodes were studied by FESEM, XRD, FTIR and elemental analysis. Based on galvanostatic charge/discharge measurements, the CN(450)/rTWTA/Ti electrode exhibited the highest specific capacitance up to 22 mF/cm2 at 0.3 mA/cm2 with long cyclic durability at 96.8% capacitance retention after 500 cycle. This effect was attributed to the existence of higher nitrogen content, more active sites, the improved hydrophilicity and three-dimensional morphology of the CN(450)/rTWTA/Ti electrode as compared to the other electrodes. This research introduces the optimum thermal condensation temperature of the melamine for synthesis of the g-C3N4 with great potentials in supercapacitors.
关键词： Supercapacitor,TiO2 nanowires/nanotubes array,Processing temperature,g-C3N4,Specific capacitance
更新于2025-09-19 17:15:36
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Promotion impact of thermal oxidation etching to saturable absorption performance of g-C3N4
摘要： A facile thermal modification method based on thermal oxidation etching was successfully developed as an effective way of improving the photoelectric properties of graphite carbon nitride (g-C3N4), and the as-prepared modified g-C3N4 was employed as the saturable absorber (SA) for a passively Q-switched Nd:LLF laser at 1.06 μm to improve the laser performance. Under the incident pump power of 7.68 W, a pulsed laser output with 110 ns pulse width at 95.5 kHz pulse repetition rate was achieved, which was the narrowest among the g-C3N4 materials used as SAs around 1 μm.
关键词： Q-switched laser,2D materials,g-C3N4 saturable absorber,Infrared lasers
更新于2025-09-19 17:15:36
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Photocatalytic Dye and Cr(VI) Degradation Using a Metal-Free Polymeric g-C3N4 Synthesized from Solvent-Treated Urea
摘要： The development of visible-light-driven polymeric g-C3N4 is in response to an emerging demand for the photocatalytic dye degradation and reduction of hexavalent chromium ions. We report the synthesis of g-C3N4 from urea treated with various solvents such as methanol, ethanol, and ethylene glycol. The samples were characterized and the Williamson–Hall method was applied to investigate the lattice strain of the samples. The activity of the samples was evaluated by observing the degradation of methyl orange and K2Cr2O7 solution under light irradiation. Photocatalytic reaction kinetics were determined as pseudo-first-order and zero-order for the degradation of methyl orange and reduction of hexavalent chromium, respectively. Due to the inhibited charge separation resulting from the small lattice strain, reduced crystal imperfection, and sheet-like structure, g-C3N4 obtained from ethanol-treated urea exhibited the highest activity among the evaluated samples.
关键词： solvent-treated urea,Cr(VI) reduction,g-C3N4,photocatalytic degradation
更新于2025-09-19 17:15:36
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Enhanced photocatalytic activity of Ag-CsPbBr3/CN composite for broad spectrum photocatalytic degradation of cephalosporin antibiotics 7-ACA
摘要： A visible-light-induced antibiotics degradation system based on a nano-Ag, CsPbBr3 quantum dot (QDs) and bulk g-C3N4 (CN) ternary assembly (Ag-CsPbBr3/CN) has been firstly constructed under an organic phase environment, oleylamine (OLA) and oleic acid (OA) were used as surfactants to stabilize the CsPbBr3, L-cysteine was used to facilitate the interaction between nano-Ag, CsPbBr3 and CN. The new ternary assembly of Ag-CsPbBr3/CN composite was used to degrade 7-aminocephalosporanic acid (7-ACA) under visible light irradiation, and the 7%-Ag-CsPbBr3/CN composite displayed the superior photocatalytic activity, approximately 92.79% of 7-ACA has been degraded to CO2, H2O and other small molecules at 140 min, which was approximately 1.49-folds, 1.56-folds, 3.01-folds and 11.43-folds higher than 9%-CsPbBr3/CN, 7%-Ag/CN, pure CN and pure CsPbBr3, respectively. A possible mechanism for 7-ACA degradation over Ag-CsPbBr3/CN composite were proposed according to detailed measurements of adsorption test, Brunauer-Emmett-Teller (BET) measurement, UV-vis diffuse reflectance spectra (DRS), photoluminescence spectra (PL), transient photocurrent response and electrochemical impedance spectroscopy (EIS) measurement, and the enhanced photocatalytic activity of Ag-CsPbBr3/CN composite could be attributed to the excellent adsorbability, the enhanced light-harvesting and reduced charge recombination, as well as the synergistic effects of nano-Ag and CsPbBr3 co-loaded with CN. In addition, Holes (h+) and hydroxyl radicals (·OH) played major roles, electronic (e-) and superoxide radical (·O2-) played minor roles based on the reactive-species-trapping experiments, the NBT transformation and the 7-hydroxycoumarin fluorescent experiments. Furthermore, a possible 7-ACA degradation pathway was investigated based on the Liquid Chromatography-Mass spectroscopy (LC-MS) experiment to better understand the degradation process. The present opens up a new insight for using CsPbBr3 as photocatalyst to degrade antibiotics.
关键词： CsPbBr3 QDs,Nano Ag,7-aminocephalosporanic acid.,Degradation,Bulk g-C3N4
更新于2025-09-19 17:15:36
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Comparison of TiO <sub/>2</sub> and g-C <sub/>3</sub> N <sub/>4</sub> 2D/2D nanocomposites from three synthesis protocols for visible-light induced hydrogen evolution
摘要： Knowledge of the interfacial structure of nanocomposite materials is a prerequisite for rational design of nanostructured photocatalysts. Herein, TiO2 and g-C3N4 2D/2D nanocomposites were fabricated from three distinct synthetic protocols (i.e., co-calcination, solvothermal treatment and charge-induced aggregation), showing different degrees of enhancement (1.4–6.1 fold) in the visible-light induced photocatalytic hydrogen evolution reaction compared to the simple physical mixture. We propose that the interfacial Ti–O–N covalent bonding promotes the charge carrier transfer and separation more effectively than the electrostatic interaction, thus accelerating the photocatalytic H2 production. Meanwhile, the exposed surface area of TiO2 in the composite needs to be enlarged for deposition of the co-catalyst. This research sheds light on the rational design of hybrid nanocomposites based on earth-abundant elements for photocatalysis.
关键词： visible light,TiO2,nanocomposites,g-C3N4,photocatalysis,hydrogen evolution
更新于2025-09-19 17:15:36