Modification Of g-C3N4 Research Articles

Amyloid-Like Protein-Modified Carbon Nitride as a Bioinspired Material for Enhanced Photocatalytic CO2 Reduction.

Modification of g-C3N4 with metal-free biomaterials through an environmentally friendly, low-energy, facile, and rapid single-step method is desired for the preparation of photocatalysts with efficient activity and high selectivity of CO2 reduction but remains a great challenge. Herein, we develop a phase-transitioned protein modification strategy for photocatalysts through superfast amyloid-like protein assembly on surfaces using a one-step sequential coating method. Metal-free carbon nitride/protein heterojunction composite photocatalysts (the phase-transitioned lysozyme (PTL), phase-transitioned bovine serum albumin (PTB), and phase-transitioned ovalbumin (PTO)-coated carbon nitride@SiO2 (CN@SiO2) and bioinspired carbon nitride hollow nanospheres (CN-HS) obtained by etching of CN@SiO2) are prepared using lysozyme, bovine serum albumin, and ovalbumin. The insulator-semiconductor heterojunctions formed at the protein-carbon nitride interface promote the migration and separation of photogenerated charges. The exposed hydrophobic alkyl and aryl groups of the surface-modified protein enable the formation of a CO2-aqueous solution-photocatalyst three-phase interface on the catalyst surface and the exposed -NH2 groups provide sites for CO2 adsorption, which effectively increases CO2 mass transfer and its adsorption as well as hydrophobicity, promoting CO2 reduction and inhibiting hydrogen production. Therefore, protein modification effectively improves the CO2 reduction activity and CO selectivity. For instance, compared to CN-HS, the CO yield of the PTL-modified CN-HS (1346.5 μmol g-1) increased by 24.5 times and the CO selectivity reached 90.5%. These findings represent a critical advancement in the surface modification of carbon nitride for CO2 reduction and the design of bioinspired materials for various applications.

Construction of S/g-C3N4@β-Bi2O3 heterojunction and its photocatalytic degradation of toluene in the gas phase.

In this paper, a modification of g-C3N4 was carried out by combining non-metal doping with the construction of heterojunctions, and a type II heterojunction composite, S/g-C3N4@β-Bi2O3, was prepared. The phase structure, morphology, elemental composition, valence band structure, and light absorption performance of the photocatalyst were analyzed using characterization techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS). The performance of the composite photocatalyst in the photocatalytic degradation of gaseous toluene, one of the typical volatile organic compounds (VOCs), under simulated solar light was studied. The effects of preparation conditions, toluene concentration, and recycling on the photocatalytic performance of the composite photocatalyst were investigated. The results show that under the optimal preparation conditions, S/g-C3N4@β-Bi2O3 achieved a degradation efficiency of 74.0% for 5ppm toluene after 5h of light irradiation. Although the degradation efficiency decreased to 61.2% after five cycles, it maintained 83% of its initial activity, indicating good stability of the composite photocatalyst. Free radical quenching experiments demonstrated that h+ was the main active species in the photocatalytic degradation of toluene, followed by ·O2-. Based on all experimental results, the migration law of photo-generated charges was analyzed, and a possible photocatalytic mechanism was proposed. In this study, a new material was obtained for the photocatalytic removal of VOCs by improving the photocatalytic properties of g-C3N4.

Photodegradation of Polycyclic Aromatic Hydrocarbons Under Visible Light Using Modified g-C3N4 as Photocatalyst, Spectroscopic Studies

In this work, visible light was used for the photodegradation of polycyclic aromatic hydrocarbons (PAHs) using graphitic carbon nitride (g-C3N4) and it was modified as a photocatalyst. Modification of g-C3N4 was performed using SDS, MIL-101, and TiO2. The UV–Vis spectroscopy, XRD, and FTIR spectrometry were applied for characterization. The photodegradation of pyrene and anthracene was investigated using the photocatalyst. Results indicated that the modified photocatalytic has better photocatalytic properties than that unmodified due to the more surface area and better optical properties of the former. Results also revealed that the photodegradation efficiency significantly improved by using g-C3N4@TiO2 so that it degrades about 95% of the pyrene molecules within 12 h. While g-C3N4@ SDS and g-C3N4@ MIL-101 are degraded very low (below 10%) under the same circumstances. The LED lamp (8 W) was used as a source of radiation. Photodegradation of anthracene was also investigated; results revealed that the anthracene is degraded more quickly than the pyrene, so that after 6 h about 98% of anthracene is decomposed. The mechanism of photodegradation was discussed.

Visible light- and dark-driven degradation of palm oil mill effluent (POME) over g-C3N4 and photo-rechargeable WO3.

The investigations of real industrial wastewater, such as palm oil mill effluent (POME), as a recalcitrant pollutant remain a subject of global water pollution concern. Thus, this work introduced the preparation and modification of g-C3N4 and WO3 at optimum calcination temperature, where they were used as potent visible light-driven photocatalysts in the degradation of POME under visible light irradiation. Herein, g-C3N4-derived melamine and WO3 photocatalyst were obtained at different calcination temperatures in order to tune their light absorption ability and optoelectronics properties. Both photocatalysts were proven to have their distinct phases, crystallinity levels, and elements with increasing temperature, as demonstrated by the ultraviolet-visible spectroscopy (UV-Vis), X-ray diffraction analysis (XRD), thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) results. Significantly, g-C3N4 (580°C) and WO3 (450°C) unitary photocatalysts exhibited the highest removal efficiency of POME without dilution due to good crystallinity, extended light absorption, high separation, and less recombination efficiency of electron-hole pairs. Furthermore, surprisingly, the superior energy storage photocatalytic performance with outstanding stability by WO3 achieved an approximately 10% increment during darkness, compared with g-C3N4 under visible light irradiation. Moreover, it has been proven that the WO3 and g-C3N4 photocatalysts are desirable photocatalysts for various pollutant degradations, with excellent visible-light utilization and favorable energy storage application.

High performance catalyst for metal catalysis coupled with photocatalysis and its catalytic ammonia borane methanolysis for hydrogen production

In the study, the influence and mechanisms of metal and non-metal dopants on the photochemical properties of the semiconductor catalyst g-C3N4 are investigated. The results reveal that doping Ni, Ru, and B on g-C3N4 results in significant alterations to the energy band structure, the band gap value decreases to 0.78 eV (Ru@g-C3N4), 0.69 eV (Ni@g-C3N4), 0.5 eV (RuB@B-g-C3N4), and 0.1 eV (NiB@B-g-C3N4) from the original value of 1.139 eV. The doping of metal and non-metal atoms can significantly enhance the light absorption capability and photothermal conversion efficiency of B-g-C3N4. The mechanism of ammonia borane (AB) dehydrogenation follows the stepwise dehydrogenation principle. AB molecules adsorb onto the active metal centers, and with the assistance of the catalytic sites, CH3OH molecules activate and attack the B–N bond in AB molecules, leading to the initial breakage of the B–N bond, the interaction between O atoms in CH3OH and N atoms in AB continues, forming NH3BH2(OCH3). Interactions between H(B) and H(O) result in the production of H2, the energy barrier for this reaction is 34.14 kcal/mol. Compared to dark conditions, RuB@B-g-C3N4 exhibits higher catalytic activity under light irradiation, the reaction time from 9′20″ reduce to 8′. This shows that there is a synergistic effect between photocatalytic AB methanolysis and conventional metal catalyzed AB methanolysis in the RuB@B-g-C3N4 catalytic system. The study provides the novel way for the development of dual-function catalysts combining metal catalysis and photocatalysis through Ru and B modification of g-C3N4.

Effect of alkali metal cation doping in graphitic carbon nitride towards photocatalytic generation of hydrogen peroxide under direct sunlight

H2O2, a powerful oxidant with a vast number of industrial applications, is being synthesized by the energy intensive anthraquinone process. Recently, H2O2 has been synthesized using H2O and O2 by photocatalysis. Graphitic carbon nitride (g-C3N4) is a popular low-cost photocatalyst that is known to produce H2O2. However, the properties g-C3N4 needs to be tailored to improve the yield of H2O2. We discuss such a modification of g-C3N4 by alkali metal cation doping. Among the Li+, Na+ and K+ ions, doping of 10 wt% of K+ in g-C3N4 increase the yield of H2O2 (200 μmol g−1 h−1) by 2.5 times as compared un-doped g-C3N4 under natural sunlight.

Effective detection of acetone by ZnFe2O4 microspheres decorated with g-C3N4 nanosheets

A single SMO limits the adsorption of gas, resulting in poor performance of the gas sensor. Herein, two-dimensional (2D) graphitic carbon nitride (g-C3N4) were modified on ZnFe2O4 microspheres as efficient gas sensing materials via hydrothermal route. The modification of g-C3N4 can alter the energy band structure of ZnFe2O4, resulting in an increase in the bandgap, thus, effectively optimizing the carrier concentration in ZnFe2O4 and elevating the baseline resistance of ZnFe2O4/g-C3N4 microspheres. The sensor based on ZnFe2O4/g-C3N4-20 microspheres (mass ratio of ZnFe2O4: g-C3N4 =10:2) had a higher response value (53.3) which was 3.4 times higher than that of ZnFe2O4, better selectivity and rapid response/recovery speeds towards 100 ppm acetone, as well as a low detection limit of 255 ppb. The enhanced performance of ZnFe2O4/g-C3N4 microsphere could be ascribed to the catalysis of C3N4, regulating the energy structure, and heterojunction formation between ZnFe2O4 and g-C3N4. Thus, this work demonstrated their promising applications in various fields.

Dual-modification strategy of Co(II) and g-C3N4 to CuS for efficient colorimetric determination of thioglycolic acid in daily cosmetics

A conventional colorimetric method based on CuS-catalyzed H2O2 is improved by a dual-modification strategy and employed for thioglycolic acid (TGA) determination. The doping of Co(II) can enhance ion exchange efficiency. Meanwhile, the modification of g-C3N4 can increase specific surface area and decrease unspecific aggregation. The constructed g-C3N4/Co-CuS nanocomposite exhibited a favorable catalytic feature. A Michaelis constant (Km) value of 0.02 mM has been achieved, which is 1/160 ofthose of CuS and horseradish peroxidase (HRP). The g-C3N4/Co-CuS displays a rapid color response in 3min and resulted in a stable measurable signal within 10min. In the determination procedure, the sulfhydryl contained in TGA is capable of preventing TMB oxidation via competing the ·OH produced by catalysis and caused a color distinction that is related to the TGA amount. The distinctions of absorbance (λmax = 652nm) of different concentrations of TGA are recorded. Linearity is obtained in the ranges of 2.5 - 20µM and 20 - 160µM, and the LOD is 0.14µM. In the real sample assays of perm agent and Qianhu lake water, the recoveries were 96.70 - 106.84% and 100.21 - 101.90%, respectively. This demonstrates that the proposed dual-modification strategy for CuS contributes to highly efficient and convenient determination of TGA in daily cosmetics and water analysis.

Direct Z-scheme g-C3N4/TiO2 heterojunction porous nanotubes: An ingenious synthesis strategy to enhance photocatalytic activity

Photocatalysis has a broad prospect for generating H2 and reactive oxygen species. In this study, porous nanotubular g-C3N4/TiO2 photocatalysts were obtained via electrospinning combined with an innovative vapor deposition approach. The waste foam was used as the precursor material for TiO2 nanotubes, reducing production cost and benefiting resource recovery. The modification of g-C3N4 onto TiO2 nanotubes provided extensive active sites with an increased specific surface area and produced the heterojunction to improve charge separation. The g-C3N4/TiO2 nanotubes displayed remarkable photocatalytic effects in the degradation of organic dye with a removal efficiency of 93.4% and H2 evolution reaction performing at 4122 μmol·g−1·h−1 under simulated sunlight. Photocatalytic activation product analyses and density functional theory (DFT) calculations demonstrated a possible photogenerated carriers transfer pathway. This work provides a way to prepare multifunctional porous nanotubes using a facile synthesis method from abandoned resources with implications for environmental remediation and hydrogen generation.

Effects of the electron-beam-induced modification of g-C3N4 on its performance in photocatalytic organic dye decomposition

Graphitic carbon nitride (g-C3N4) was irradiated with an electron beam (EB) to improve the photocatalytic efficiency of Rhodamine B (RhB) decomposition. EB irradiation up to 200 kGy improved the efficiency of RhB decomposition, whereas further EB irradiation lowered the reaction efficiency. The chemical structure and textural properties of g-C3N4 were altered via EB irradiation. Low-dose EB irradiation introduced structural defects in g-C3N4 and increased its surface hollow depth, resulting in improved photocatalytic efficiency. In contrast, high-dose EB irradiation decreased the surface hollow depth, probably owing to intense structural destruction following recomposition.

Modification of g-C3N4 with hydroxyethyl cellulose as solid proton donor via hydrogen bond to enhance H2O2 production

Hydroxyethyl cellulose (HEC) is used as a solid proton donor to modify graphitic carbon nitride (g-C3N4) via non-covalent bonds to improve H2O2 production performance. The modified g-C3N4 (CN/HEC) is prepared by stirring the suspension of g-C3N4 and HEC at room temperature and drying. The H2O2 production efficiency of CN/HEC is 3.89 times that of g-C3N4. Both experimental results and density functional theory calculations (DFT) suggest charge transfer from HEC to g-C3N4 and hydrogen bond formation between HEC and g-C3N4. CN/HEC possesses higher charge separation efficiency than g-C3N4. Stability test, XPS, FTIR, and DFT analyses suggest that HEC acts as a proton donor. The synergy of charge separation enhancer and proton donor from HEC promotes the sequential two-step single-electron O2 reduction for H2O2 production. This study explores a way to utilize cellulose material as solid proton donors to modify g-C3N4 via hydrogen bonds under mild conditions for increased H2O2 production performance.

Enhanced boron modified graphitic carbon nitride for the selective photocatalytic production of benzaldehyde

Graphitic carbon nitride is a non-metal photocatalyst easily prepared from nitrogen organic compounds through green synthesis processes that do not require the use of solvents. This work proposes the use of boron to modify the layered g-C3N4 structure by incorporating B to induce defects aimed at the enhancement of the photocatalytic activity. Boron-modified graphitic carbon has been obtained using elemental B and NaBH4 as precursors. The XRD and FTIR characterization results suggest that the C and N positions of g-C3N4 can be replaced by B, resulting in a layered modified structure in which the tri-s-triazine units are altered. The exchange of B atoms differed from the boron precursor according to the analysis of the chemical properties of the surface. Thus, the elemental B had a preference to exchange positions with N atoms, whereas the use of NaBH4 led to the substitution of B into the C positions. This difference considerably affected the photocatalytic activity during the selective oxidation of benzyl alcohol. The sample modified with NaBH4 led to the highest oxidation rate and selectivity linked to a lesser recombination effect than the other samples according to photoluminescence tests. This work provides evidence about the convenience of the selection of precursors during the modification of g-C3N4. The photon absorbance rate was determined for the estimation of the quantum yield. Although the photon absorbance rate was quite similar in all the cases, the different registered kinetics led to a maximum quantum efficiency of 0.15% for NaBCN.

A novel strategy to construct a direct Z-Scheme Bi@Bi2O2CO3/g-C3N4 heterojunction catalyst via PDA electronic bridge

A novel strategy was employed to construct Z-Scheme Bi@Bi2O2CO3/PDA/g-C3N4 (BPCN) heterojunction through polydopamine (PDA) modification of g-C3N4 followed by deposition of Bi2O2CO3 component to efficiently remove tetracycline (TC) from water, in which PDA served as the electron transfer bridge and reductant for Bi reduction. The surface plasma resonance (SPR) effect of Bi nanoparticles and conjugated π structure shared between PDA and g-C3N4 can delocalize π-π* electrons thus promote the transport of carriers synergistically. The 10% BPCN catalysts showed much higher photocatalytic activities than single Bi2O2CO3, g-C3N4, and dual PDA/g-C3N4. The phase structure, morphology features, optical absorption and photoelectrochemical properties of BPCN were investigated in depth. Furthermore, the possible TC degradation pathway has been established based on liquid chromatography-mass spectrometry (LC-MS) analysis, and the acute toxicity LD50 of rat, bioconcentration factor, developmental toxicity and mutagenicity of TC and its degraded intermediates were evaluated based on quantitative structure activity relationship (QSAR).

An efficient ternary photocatalyst Ag/ZnO/g-C3N4 for degradation of RhB and MG under solar radiation

Industrial dyes are the crucial reason for water contamination. Due to their recalcitrant nature, these toxic dyes represent a significant risk to aquatic creatures as well as carcinogens to human beings. The common methods used for the removal of dyes for example electro-coagulation, reverse-osmosis, and ultra-filtration are cumbersome, expensive, and non-repeatable. In this study, a cost-effective, environmentally benign, and recyclable nano-composite material for effective solar photodegradation of Rhodamine B (RhB) and Malachite green (MG) was discussed. Silver doped ZnO nanoparticle modified g-C3N4 was fabricated by chemical precipitation procedure where melamine was taken as a precursor. The results showed that the modification of g-C3N4 with Ag/ZnO has increased activity under visible light and is suitable for photodegradation when compared to the neat g-C3N4. The percentage of dye degradation increased with an increase in agitation time. The efficiency was almost 97% for RhB in 30 ​min and 91% for MG with Ag/ZnO/g-C3N4 in 60 ​min. The deprivation of dye by the photocatalytic nanocomposite was studied using first-order kinetics. The First-order rate constant (K) determined by using ternary nanocomposite Ag/ZnO/g-C3N4 had a greater reactivity than the pure g-C3N4. The most important reactive species in the photocatalytic reaction over Ag/ZnO/g-C3N4 are detected as superoxide radicals (O2−•) and hydroxyl radical (OH•) by using the quenching test. Several sophisticated techniques like powder XRD, SEM, EDAX, FTIR, and UV–Vis DRS were used for the characterization of synthesized nanocomposites. Doping of Ag nanoparticles has increased the response towards visible light for g-C3N4 and also an increase in the rate of photogenerated electrons thereby reducing electron-hole recombination.

Exfoliation-induced exposure of active sites for g-C3N4/N-doped carbon dots heterojunction to improve hydrogen evolution activity

Photocatalysis is a surface catalytic process in which photogenerated electrons are transferred to the surface of the catalyst for water reduction. In this paper, we described a novel two-step calcination strategy that not only realizes the integrating of N-doped carbon dots (NCDs) with g-C3N4 nanosheets, but also can the g-C3N4/NCDs heterojunction provide more catalytic active sites and shortens the distance of charges transport to the surface of materials. The first thermal treatment in the air lead to the formation of bulk g-C3N4 while NCDs was loaded in it. The subsequent secondary calcination was conducive to the exfoliation of bulk g-C3N4 into thinner nanosheets with thickness of 1 nm. Meanwhile, more NCDs insetted in the pristine g-C3N4 were exposed to the surface of materials and more catalytic active site were formed, thus promoting the hydrogen evolution. Electron paramagnetic resonance (EPR) tests certified that the g-C3N4 nanosheet/NCDs composites can generate more OH radical compared with bulk g-C3N4 and bulk g-C3N4/NCDs, which further validated that photogenerated electron-hole was effective separated due to more exposure of NCDs and shorter distance of electron transport to the surface. Impressively, results showed that modification of g-C3N4 with NCDs (1.0 wt % loading) exhibited the highest photocatalytic hydrogen production rate (3319.3 μmol g−1 h−1) and an apparent quantum yield of 29.8 % at 420 nm, which was 13 folds of bulk g-C3N4. Our work illuminates a new method for high activity g-C3N4/carbon dots photocatalyst in the field of photocatalysis.

Recent developments of doped g-C3N4 photocatalysts for the degradation of organic pollutants

Graphitic carbon nitride (g-C3N4), with a moderate band gap (∼2.7 eV), high chemical and thermal stability, has been the hotspot in environmental photocatalysis. However, its performance is still unsatisfactory because of insufficient absorption of visible light, poor surface area, low electronic conductivity and high recombination rate of photogenerated electron-hole pairs. The modification of g-C3N4 could overcome these problems to improve photocatalytic properties. Among various modification strategies, element doping is an efficient and simple strategy for adjusting electronic structure and accelerating photocatalytic performance. This review focused on the progress and trends of designing typical, cost-effective element-doped carbonized nitrogen and its degradation of environmental organic pollutants. The heterogeneous catalytic mechanisms of g-C3N4-based photocatalysts for organic pollutants degradation have been explicated in detail. The increased photocatalytic performance of g-C3N4 by doping various elements was discussed clearly. The surface properties, catalyst performance and pollution management of various elements-doped g-C3N4 were compared and subsequently analyzed some dilemmas and application strategies for g-C3N4 development in depth. This review can light up a new way and afforded valuable clues to design g-C3N4 doping elements to exploit more effective photocatalyts for real applications in environmental pollution management.

Z-scheme heterojunction g-C3N4@PDA/BiOBr with biomimetic polydopamine as electron transfer mediators for enhanced visible-light driven degradation of sulfamethoxazole

Visible-light photocatalysis boosted by Z-scheme photocatalysts has been deemed as an economic and effective way in eliminating emerging antibiotics pollution. A Z-scheme heterojunction photocatalyst g-C3N4@PDA/BiOBr (CNPB) was hereby facilely constructed through polydopamine (PDA) modification of g-C3N4 followed by deposition of BiOBr component via a solvothermal reaction. The structure, morphology, optical and photoelectrochemical properties etc. of CNPB were characterized and explored. The photocatalytic activity of CNPB was assessed on the degradation of sulfamethoxazole (SMX). CNPB manifested remarkably improved photocatalytic performance than the as-prepared g-C3N4, BiOBr and g-C3N4/BiOBr heterojunction in the degradation of SMX under visible light irradiation. SMX could be nearly completely degraded in 60 mins by CNPB, while the degradation rate of SMX under g-C3N4, BiOBr, g-C3N4/BiOBr heterojunction, and the “g-C3N4@PDA + BiOBr” mixture were 30%, 42%, 71%, and 47%, respectively. The highly enhanced photocatalytic efficiency of CNPB was attributed to the synergistic effect of improved light harvesting and accelerated transport and separation of photo-generated carriers in the Z-scheme structure with PDA as efficient electron transfer mediators. A Z-scheme charge transfer mechanism was confirmed by experiments on radical scavenging and electron spin resonance (ESR) signals trapping, which demonstrated that the h+ and O2− were the major reactive species in oxidizing SMX. The degradation mechanism, main intermediates and reaction pathways were further explored. Besides, CNPB exhibited good stability and reusability in multiple uses. The construction of Z-scheme photocatalyst using biomimetic polydopamine as electron transfer mediators may provide an insight into designing new and efficient photocatalysts for environmental applications.

Enhanced antifouling property of fluorocarbon resin coating (PEVE) by the modification of g-C3N4/Ag2WO4 composite step-scheme photocatalyst

In the complex ocean environment, the attachment of marine creatures to the hull of a ship and to marine infrastructure has been a highly important problem. Ag2WO4 is an effective photocatalytic material and bacteriostatic agent that has seen only limited application due to its lack of optical stability and low quantum yield, necessitating the further development of this material. In this work, a fluorocarbon resin coating (PEVE) is used as the matrix and is modified by g-C3N4/Ag2WO4 composite catalysts. Experimental results show that the modified coating exhibits excellent antibacterial ability and cycle stability under visible light. The Step-scheme heterojunction between g-C3N4 and Ag2WO4 inhibited the recombination of the photogenerated electron-hole pairs in the photocatalyst and enhanced the photocatalytic activity and stability. The presence of g-C3N4 contributes to the formation of the beta (β)-Ag2WO4 metastable phase, and the mechanism contributing to the phase transformation was examined by first-principle calculations for the first time.

Switching between negative and positive electrorheological effect of g-C3N4 by copper ions doping

Investigation of pristine g-C3N4 and copper ions doped g-C3N4 as dispersed phases in silicone-oil based electrorheological (ER) fluids is reported for the first time. Pristine g-C3N4 was prepared via standard thermal polycondensation of urea. Introduction of Cu ions into g-C3N4 polymeric network was performed by treatment of pristine powder by a solution containing tetraammoniumdiaquacopper(II) complex ions followed by annealing. The structure and properties of products were revealed with the aid of XRD, FTIR, UV–Vis and XPS, and complemented by SEM investigation of morphology, pycnometry, BET analysis, and conductivity measurements. The response of prepared ER fluids to an external electric field was examined by rheometry and the effects visualized with optical microscopy. While ER fluids based on g-C3N4 exhibited negative ER effect (decrease in viscosity when the field is switched-on), ER fluids based on a g-C3N4/Cu-doped analogue exhibited positive ER effect. Dielectric spectroscopy using Havriliak-Negami model revealed that introduction of the dopant almost doubled the dielectric relaxation strength while the relaxation time was halved. The ability of g-C3N4/Cu as a candidate for further studies necessary to increase the ER effect was demonstrated. Thereto, described modification of g-C3N4 by copper ions shall be applicable also for other metals forming ammonia complexes.

Au/Pd/g-C3N4 nanocomposites for photocatalytic degradation of tetracycline hydrochloride

The arbitrary discharge of antibiotic residuals has seriously influenced the ecosystem and human health. Photocatalytic degradation of antibiotic residuals with semiconductor photocatalyst is considered to be more effective method due to its unique superiority. Herein, Au/Pd/g-C3N4 nanocomposites were synthesized by loading Au and Pd nanoparticles on the surface of g-C3N4 sheets for photocatalytic degradation of tetracycline hydrochloride. The modification of g-C3N4 with Au and Pd nanoparticles efficiently enhanced the visible-light absorption, improved the separation and transfer of photogenerated electrons and decreased the recombination of electron–hole pairs. As-prepared Au/Pd/g-C3N4 nanocomposites exhibited improved photocatalytic performance with more than 90% degradation rate. Furthermore, the good stability and reusability of Au/Pd/g-C3N4 nanocomposites would be beneficial to further photocatalytic degradation application.