Ternary Carbon Research Articles

Ternary Carbon Spheres/PAA-Al2O3 Nanoparticles as an Efficient Catalyst for RhB Dye Degrader and Bactericidal Agent; Molecular Docking Analysis

Ternary Carbon Spheres/PAA-Al2O3 Nanoparticles as an Efficient Catalyst for RhB Dye Degrader and Bactericidal Agent; Molecular Docking Analysis

Construction of dual Z-scheme ternary carbon nitride homojunction pectin microspheres as a multifunctional photocatalyst for tetracycline degradation, H2O2 production, and N2 fixation

Graphitic carbon nitride (GCN) has gathered phenomenal research interest as a metal-free, safe, and affordable photocatalyst. However, GCN suffers several problems, such as lower utilization of visible light, higher recombination ratio, slower electron immobility, poor reusability, and a tedious recovery process. Herein, a ternary homojunction (OPACN) was effectively constructed between oxidized GCN (OCN), amino-rich GCN (ACN), and phosphorylated GCN (PCN) and then formulated into 3D hydrogels (OPACN) using pectin as the catalyst support via a crosslinking strategy using FeCl3. The photocatalytic studies using OPACN hydrogel reported 88 % degradation of tetracycline in 30 min with a maximum reusability of 15 cycles. The ternary homojunction hydrogel photocatalyst produced 1204 µM of H2O2 and 404 µM of ammonia in 60 min of visible light irradiation. The phenomenal catalytic activity of the OPACN hydrogel is ascribed to the effective construction of homojunction between the OCN, PCN, and ACN, which facilitated the separation efficiency and boosted the visible light utilization. This study affirmed that the utilization of pectin as a catalytic support enhanced the visible light utilization, reusability, stability, and easiness in recoverability. In addition to this, pectin can act as an electron mediator, and the robust interactions between the GCN components via hydrogen bonding can also facilitate H2O2 production and nitrogen fixation. Overall, this study illuminates the usage of pectin as ideal photocatalytic support for environmental applications.

Chiral carbon dots based on ternary carbon sources: A multifunctional therapeutic agent for Cu2+-induced Alzheimer's disease

Metal dyshomeostasis is one of the pathological features of Alzheimer's disease (AD). Cu2+ is believed to induce the formation of neurotoxic β-amyloid (Aβ) aggregates and aggravate oxidative damage. It is challenging to take effective therapeutic interventions towards the complicated pathogenesis related to Cu2+. Herein, chiral carbon dots were proposed for Cu2+-related AD therapy. The chiral CDs were prepared based on the ternary carbon sources, using L/d-cysteine as the chiral carbon source, citric acid as the carbonization source and β-cyclodextrin as the chirality inducer, reserving and enhancing the chirality of CDs. Compared to L-Cys-CDs, D-Cys-CDs exhibited enhanced chirality, stronger affinity towards Cu2+ and comparable antioxidant ability, but better inhibition on peroxidase-like activity of Cu2+ or Aβ42-Cu2+. Thus, D-Cys-CDs performed better to inhibit Cu2+-induced Aβ aggregation. Meanwhile, D-Cys-CDs can alleviate the cytotoxicity of Aβ42-Cu2+ with satisfactory anti-inflammation effect and scavenging ability towards intracellular reactive oxygen species. D-Cys-CDs succeeded in reducing Aβ deposits and releasing paralysis for the AD model CL2120 nematodes. D-Cys-CDs with an enantiomeric effect on Cu2+-induced Aβ aggregation and the peroxidase-like activity of Cu2+ was promising as the multifunctional therapeutic agent for Cu2+-induced AD therapy.

Red emissive fluorescent carbon dots based on ternary carbon source for imaging α-synuclein fibrils

The misfolding and aggregation of α-synuclein monomers usually cause the occurrence and development of Parkinson’s disease (PD). It is important to develop effective methods for detection of α-synuclein aggregates. Carbon dots (CDs) could be the potential fluorescence probe for this purpose owing to their appreciated optical properties. However, undefined structure of CDs and complicated three-dimensional structure of protein severely hindered the design of fluorescence probe towards protein aggregates. Herein, a red emissive fluorescent amphiphilic CD, named as CL-9, was designed with a high sensitivity to α-synuclein fibrils by a one-step heating process, using the ternary carbon source, including Congo red, l-tryptophan and urea. The CL-9 exhibited turn-on red emissive fluorescence towards α-synuclein fibril, but remained no change towards its monomer. Compared with the original Congo red dye, CL-9 exhibited stronger turn-on red fluorescence towards α-synuclein fibrils with better anti-photobleaching resistance, biocompatibility and signal-to-noise ratio. The CL-9 was successful as a fluorescent probe to image α-synuclein fibrils in NL-5901 C. elegans. The present study provided a feasible approach using the multiple carbon sources to construct the CDs based fluorescence probe targeting amyloid proteins.

Novel ternary Z scheme carbon quantum dots (CQDs) decorated WS2/PANI ((CQDs@WS2/PANI):0D:2D:1D) nanocomposite for the photocatalytic degradation and electrochemical detection of pharmaceutical drugs

The endocrine-disrupting chemicals (EDCs) and antibiotics are causing negative effects on human beings and animals by disrupting the endocrine system and spreading antimicrobial resistance. The current need is to eradicate pharmaceutical waste from water bodies using advanced catalytic systems with high efficiency. Novel ternary carbon quantum dots (CQDs) decorated Z-Scheme WS2-PANI nanocomposite was prepared by a green synthesis assisted in-situ polymerization for the photodegradation and detection of Estradiol (EST) and Nitrofurantoin (NFT). HRTEM micrographs revealed the formation of CQDs with a mean size of 4 nm anchored on the surface of WS2/PANI (width:PANI ∼ 20-30 nm). The ternary nanocomposite showed excellent photocatalytic activity, degraded NFT (95.7% in 60 min), and EST (96.6% in 60 min). The rate kinetics study confirms the reaction followed pseudo first-order model. This heterostructure exhibited enhanced performances by modulating the energy level configuration, enhancing the absorption of visible light (2.4 eV), and significantly improving the charge separation, three times higher than pristine WS2. These are highly favorable for increasing the generation of photoinduced charges and enhancing the overall performance of the catalyst. Further, the electrochemical sensor was prepared using CQDs@WS2/PANI composite on a paper-based electrode. The CQDs@WS2/PANI exhibit a linear response of 0.01 to 100 nM, with a limit of detection of 13 nM. This synergistic interfacial interaction resulted in the significantly improved electrochemical performance of the modified electrode. The proposed Z-scheme was justified by electron paramagnetic resonance (EPR) and scavenger experiment. An intermediate degradation pathway was also proposed. The synthesized materials were characterized using FESEM, HRTEM, XRD, FTIR, XPS, UV-visible, PL, and TRPL. Therefore, this study provides a direct approach to fabricate a heterojunction that combines two-dimensional, one dimensional, and zero-dimensional properties, enabling control over the energy level configuration and subsequent improvements in photocatalytic and electrocatalytic efficiency.

Constructing Sequential Type II Heterojunction CQDs/Bi2S3/TiNbO Photoanode with Superior Charge Transfer Capability Toward Stable Photoelectrochemical Water Splitting.

Efficient charge transfer and light-trapping units are pivotal prerequisites in the realm of Ti-based photoanode photoelectrochemical (PEC) water splitting. In this work, we successfully synthesized a ternary carbon quantum dots/Bi2S3 quantum dots/Nb-doped TiO2 nanotube arrays (CQDs/Bi2S3/TiNbO) composite photoanode for PEC water splitting. CQDs/Bi2S3/TiNbO composite photoanode exhibited a considerably elevated photocurrent density of 8.80 mA cm-2 at 1.23 V vs the reversible hydrogen electrode, which was 20.00 times better than that of TiO2 (0.44 mA cm-2). Furthermore, the CQDs/Bi2S3/TiNbO composite photoanode attested to exceptional stability, maintaining 92.54% of its initial current after 5 h of stability measurement. Nb-doping boosted the electrical conductivity, facilitating charge transfer at the solid-liquid interface. Moderate amounts of Bi2S3 quantum dots (QDs) and CQDs deposited on TiNbO provided abundant active sites for the electrolyte-photoanode interaction. Simultaneously, Bi2S3 QDs and CQDs synergistically functioned as light-trapping units to broaden the light absorption range from 396 to 530 nm, stimulating increased carrier generation within the composite photoanode. In comparison with pristine TiO, CQDs/Bi2S3/TiNbO photoanodes possessed a superior ability to promote interfacial reactions. This study may provide a strategy for developing high-performance Ti-based photoanodes with efficient charge transfer and light trapping units for highly driving solar-to-hydrogen conversion.

Unique synergistic effects of ternary multi-dimensional CNT/g-C3N4/MoS2 hybrid as a paraffin oil additive for improved tribological properties

Graphitic carbon nitride (g-C3N4) nanomaterials have drawn much interest in the lubrication and friction fields owing to their excellent self-lubrication and mechanical performances. However, the easy agglomeration and poor dispersion stability of single g-C3N4(CN) have always been a headache. In the work, multi-dimensional ternary carbon nanotube, graphite carbon nitride, and molybdenum disulfide (CNT, CN, and MoS2) hybrids were fabricated by hydrothermal method. The microstructure and its reinforcement impact on the tribological properties of the corresponding paraffin oil were systematically studied. The results showed that the zero-dimensional spherical MoS2, one-dimensional tubular CNT, and two-dimensional lamellar CN are uniformly compounded. The tribological test results display that average friction coefficient and wear rate of the 0.2 wt% CNT/CN/MoS2 are decreased by 39.23% and 91.97% lower than those of pure paraffin oil, CNT and CN/MoS2 with the same concentration, respectively. The significantly improved tribological properties of lubricating oil is ascribed to even dispersion of CNT, CN, MoS2 in CNT/CN/MoS2 hybrids, self-lubricating effect of MoS2 and CN, and load-bearing ability of CNT and CN nanosheets, and also the generation of lubricating film between friction pairs during the wear process.

Defect-activated ternary carbon composite: A multifunctional electrocatalyst for efficient oxidation of water, urea, glucose, ORR, and zinc-air batteries

Designing a low-cost multifunction electrocatalyst that can synergistically catalyze multiple reactions in alkaline media while operative for long periods is of paramount importance for the hydrogen economy. Particularly, defect-activated electrocatalysts can significantly improve electrolytic performance by altering their chemical properties and electronic structures. However, developing defect-rich electrocatalysts with multiple active sites for efficient electro-oxidation of water remains challenging. In this respect, we present a straightforward strategy to design a defect-activated multifunctional ternary carbon composite by integrating graphene oxide (GO), Mxene (Mx), and graphitic carbon nitride (CN). Benefiting from the well-integrated 2D interfacial coupling of different carbon nanostructures, carbon composite has several advantageous properties including superior electric conductivity, higher specific surface area, activated surface defects, and highly accessible multicomponent surface-active sites. In addition, carbon composite exhibited macroporous 3D architecture for free migration of oxygen species and electrons. Accordingly, the carbon composite served as a multifunctional electrocatalyst in alkaline media, displaying superior electrolytic activities toward oxygen evolution reaction (OER), urea oxidation reaction (UOR), glucose oxidation reaction (GOR), and oxygen reduction reaction (ORR). Moreover, the Zn-air batteries (ZABs) fabricated with Zn anode and carbon composite as air-cathode demonstrated to have a high-power density, high discharge voltage, and excellent cycling stability in alkaline media. The exceptional electrolytic performance is attributed to the defect-rich interfaces and the synergistic interactions between the multi-components of carbon composite, which not only facilitate free accessible volume for rapid diffusion of oxygen-related species but also maintain the structural integrity during the reaction, thus allowing its comparable fast reaction kinetics. Overall, this work presents a simple and scalable strategy to design an efficient, stable, and eco-friendly multifunctional electrocatalyst that has the potential to be used in a wide range of applications in energy conversion and storage.

Enhancing charge transfer utilizing ternary composite slurry for high-efficient flow-electrode capacitive deionization

Weak contact between activated carbon (AC) particles results in a poor conductivity for the electrode slurry, which limits the improved desalination performance in flow-electrode capacitive deionization (FCDI). Based on the bridging and filling effects of nanoparticles, we report a ternary composite slurry with multi-dimensional sized carbon particles by introducing the carbon nanotubes (CNT) and carbon black (CB) into AC-based slurry, namely AC/(CB + CNT) slurry. Further enhanced electrical conductivity relative to conventional pure AC slurry. By comparison analysis, FCDI system with the ternary carbon composite slurry had a faster average salt removal rate (ASAR) of 1.89 μmol cm−2 min−1 under at 1.2 V in a feed salinity of 2.0 g L−1, which is 3.27 1.92 and 1.46 times that of pure AC, AC/CB and AC/CNT slurry. In long-term operation (1800 min, U = 1.6 V), the AC/(CB + CNT) slurry exhibited a stable ASAR of 4.41 μmol cm−2 min−1 and maintained a charging efficiency (CE) of around 96% and molar energy consumption (Em) of 0.043 kWh mol−1. Electrochemical analysis and computational fluid dynamics (CFD) simulation further confirms that AC/(CB + CNT) slurry enable system with a point-to-line-to-surface connection morphology, which generates a robust charge percolation network with diverse pathway and facilitates the charge transfer. In summary, this study developed a facile strategy for increasing the slurry conductivity to provide a feasible approach in efficient desalination application.

Highly selective conversion of tetrabromobisphenol A epoxy resin waste to high-purity phenolic chemicals by subcritical water-CuO process

Tetrabromobisphenol A epoxy resin (TBBPA-ER) is the most important nonmetallic composition of waste printed circuit boards (PCBs). Currently, the TBBPA-ER waste is mainly sent to incineration or landfills. The great obstacle of the recovery of the TBBPA-ER waste is the low value-added products obtained by existing technologies. In this study, a novel resource conversion strategy was developed to produce high-purity phenolic chemicals from the TBBPA-ER waste by subcritical water-CuO (SubCW-CuO) process. The high selectivity of the SubCW-CuO process for the recovered products from the TBBPA-ER waste could be attributed to the regulating effect of CuO. The CuO could preferentially trigger the rupture of C-O and C-Ph bonds in the TBBPA-ER chain, resulting in the producing of high-purity phenol (91.47 %) at 300 °C. The reaction between phenol and methyl radical (derived from β-scission of ternary carbon chain groups in the TBBPA-ER waste) resulted in the recovery of high-purity p-cresol (90.30 %) at 350 °C. The optimal conditions of the SubCW-CuO process were solid-liquid ratio of 1:30 g/mL, M(TBBPA-ER):M(CuO) ratio of 10:1 g/g, and 60 min. The conversion ratio of the TBBPA-ER waste could reach 70 % under the optimal conditions. Approximately 3 % of the bromine was transferred into the oil phase products after the SubCW-CuO process at 250 °C, while no organic bromine could be found in the oil phase products at 300 and 350 °C. More than 70 % of the bromine was fixed in the solid residue after the SubCW-CuO process at 300 and 350 °C. The bromine contained in the solid residue mainly existed in the form of CuBr and the Cu species had efficient capture ability for the bromine released from the molecular chain of the TBBPA-ER. It is believed that the SubCW-CuO process developed in this study is a promising alternative technology for the high-efficiency resource conversion of the TBBPA-ER waste.

Sensing mechanism of a flexible strain sensor developed directly using electrospun composite nanofiber yarn with ternary carbon nanomaterials

SummaryRecently, various strain-sensing yarns have been developed without ideal stitchability. Herein, we used spherical carbon black particles (CBs), linear carbon nanotubes (CNTs), and lamellar graphene flakes (GRs) as conductive nanofillers to construct multi-element conductive networks inside a thermoplastic polyurethane (TPU) matrix. First, a highly stretchable and conductive multidimensional carbon-based nanomaterial/TPU composite nanofiber yarn was fabricated using electrospinning, which could be used as a flexible strain sensor without post-processing. Accordingly, the effects of nanomaterials’ dimensionality and synergy on yarns’ conductivity, mechanical properties, and strain sensing performances were explored. The yarn containing multiple networks formed by CB/CNT/GR ternary hybrid networks, CNT and GR auxiliary networks exhibited the best performances. Subsequently, the structural evolution of the ternary conductive network under stretching was revealed to further analyze the sensing mechanism. Finally, the yarn endowed a medicated plaster with an intelligent function to detect motions in the rehabilitation of joint pain by simple sewing.

Lignin-Derived Ternary Polymeric Carbon as a Green Catalyst for Ethyl Levulinate Upgrading from Fructose

Currently, the utilization of lignocellulose mainly focuses on the conversion of polysaccharide components to value-added chemicals, such as ethyl levulinate (EL). Lignin is an important component of lignocellulosic biomass that is often neglected. Herein, ternary polymeric carbon (TPC–S) was synthesized by polymerization of mixed monomers (4-methylphenol, 4-ethylphenol, and 4-propylphenol) derived from lignin and subsequent sulfonation, which was used as a heterogeneous catalyst for the transformation of fructose to EL. Through a series of characterization methods, it was illustrated that the prepared catalyst had a layered porous structure. The calculated carbon layer spacing is 0.413 nm, and the average pore size is 5.1 nm. This structure greatly increases the specific surface area (165.2 m2/g) of the catalyst, which makes it possible to introduce more –SO3H species in the process of sulfonation, thus furnishing EL with increased yield. The effects of reaction temperature, time, catalyst dosage, and fructose initial concentration on the production of EL were investigated. It was found that 70.3% EL yield was detected at 130 °C for 10 h. In addition, the catalyst had good stability and could obtain 65.6% yield of EL in the fourth cycle. The obtained catalyst has the advantages of low cost, easy preparation, and high catalytic efficiency, which is expected to achieve efficient utilization of lignin and provide a potential solution for the future production of EL.

Polarization-induced carrier separation in conjugated polyimide for boosted visible light driven H2O2 production

Ternary carbon nitride oxygen semiconductors have been developed as metal-free catalysts for photocatalysis, but the efficiencies are still far from satisfaction. Herein, we report that polarization adjusted conjugated polyimide (PIK) can be substantially optimized the activity of visible-light induced H2O2 production. The structures of catalyst have been well characterized by XRD, FTIR, BET and XPS. Compared with bulk polyimide, optimized PIK1.5 displays 117-folds-enhanced photocatalytic H2O2 production under visible light (λ ≥ 420 nm), achieving an excellent H2O2 production rate of 160.5 umol·g·h−1. Fluorescence spectroscopic measurements confirm that reinforced photocatalytic H2O2 production is mainly attributed to the increased polarization in conjugated polyimide, which effectively accelerates the separation and migration kinetics of electron-hole pairs. These results indicate that polarization play an important role in polymeric semiconductors for solar energy utilization.

Rational preparation of ternary carbon cloth/MnO2/polyaniline nanofibers for high-performance electrochemical supercapacitors

Rational preparation of ternary carbon cloth/MnO2/polyaniline nanofibers for high-performance electrochemical supercapacitors

In Situ Generation of Hydrogen Peroxide Using Polymetallic-Doped g-C3N4 for Pollutant Removal

Fenton reaction is a powerful technology for pollutants’ removal from water. However, the cost of H2O2 becomes one of the major stumbling blocks in its application. H2O2 has a relatively high price and is easily decomposed during transportation and use; therefore, in situ synthesis of H2O2 could improve economic benefits effectively. In this study, a Fe/Ni/Pd ternary metal-doped graphitic carbon nitride (FeNi-Pd@CN) is prepared, and in situ H2O2 generation using formic acid as hydrogen sources for organics removal was proved. The catalyst is advantageous, as H2O2 could accumulate to 1.69 mmol/L in 150 min when pumping air rather than oxygen gases in other studies. Furthermore, 92.0% of Acid Red 73 (200 mg/L) and 93.2% of tetracycline hydrochloride (10 mg/L) could be removed in 150 min without any pH adjustment. Characterization results show that the catalyst has good stability in metal leaching and reuse tests. It is proved that •OH and •O2− are the main reactive oxygen species, and a synergistic effect between Fe and Ni exists that enhances ROS generation for organics degradation. This work offers a promising method to remove refectory organic contaminants from industrial wastewater.

Construction of a ternary spatial junction in yolk–shell nanoreactor for efficient photo-thermal catalytic hydrogen generation

Highly efficient solar‐to‐hydrogen (H2) conversion depends crucially on the light-harvesting capability, cumulative cascade efficiency of photo-induced carriers, and surficial vibrant kinetics of photocatalysts. Herein, a spatially ternary carbon nanospheres@TiO2/reduced TiO2 (denoted as C@TiO2/TiO2-x) yolk–shell (YS) nanoreactor is proposed as a model solar water splitting system, in which an excellent photothermal conversion is achieved by the YS nanoreactor with carbon core as the nanoheater and its light absorption range is extended to the longer wavelength of even near‐infrared light. Spatial inside-out junctions in the nanoreactor were designed to frame multiple-level charge transfers with the Ti–O–C channel as charge transport bridge. Surface oxygen vacancy defects (OVs) induced by Ti3+ self-doping accelerate the mass transfer, trap the photo-induced electrons, and afford the active sites for proton reduction. Therefore, benefiting from the dual contributions of the heat built-up and ternary spatial junctions in the C@TiO2/TiO2-x YS nanoreactor, its photo-thermal catalytic H2 conversion activity (3667 μmol h−1 g−1) has been remarkably enhanced at least 22-fold under simulated sunlight irradiation (AM 1.5G) without the use of noble metal cocatalysts. This YS spatial junction construction strategy for cascade electron transfer in nanoreactors may be further applied to other photo-thermal catalysts for enhanced solar-to-fuel conversions.

Green synthesis of ternary carbon dots (CDs)/MIL-88B (Fe)/Bi2S3 nanocomposite via MOF templating as a reusable heterogeneous nanocatalyst and nano-photocatalyst

An environmentally friendly heterogeneous ternary carbon dots (CDs)/MIL-88B (Fe)/Bi2S3 nanocomposite was synthesized by a multistep method. In this study, we have studied low-temperature calcination with relatively inexpensive reactants. The sufficient CD arrays were generated by loading the glucose molecules into the pores of an as-obtained metal-organic framework (MOF), i.e. MIL-88B (Fe)), by heating to 200 °C. Fabricated nanocomposite structures were characterized by FT-IR, XRD, EIS, SEM, TEM, BET, and TGA techniques, demonstrating the decoration of the Bi2S3 on the CDs/MIL-88B (Fe) nanocomposite surface. MOF templating has been chosen as a systemic method for limited size CD formation inside MIL-88B (Fe) pores. The CD arrays also revealed an excellent efficacy for catalytic and photocatalytic applications. According to the experimental results, CDs/MIL-88B (Fe)/Bi2S3 with the highest electron-accepting and transporting properties capacity displayed the most increased activity as catalyst and photocatalyst. The catalytic and photocatalytic performance of obtained structures was investigated by reducing 4-nitrophenol (4-Nip) to 4-aminophenol (4-Amp) and decomposition of cationic Methylene Blue (MB) and anionic Acid Blue 92 (AB92) dyes under visible light irradiation, respectively. The current work exhibited CDs/MIL-88B (Fe)/Bi2S3 nanocatalyst as a potent multifunctional composite to remove organic components in the presence of reducing agents and visible light, which can be employed for wastewater treatment applications.

Enhanced photocatalytic activity of ternary g-C3N4/NaTaO3/biomass carbon composite photocatalysts under visible-light radiation

Highly efficient visible-light-responsive ternary graphitic carbon nitride (g-C3N4)/NaTaO3/biomass carbon (BM-C) photocatalysts with different g-C3N4 amounts were prepared via a solvothermal method combined with a high-temperature sintering method. Herein, the crystal structure and morphology of g-C3N4/NaTaO3/BM-C are investigated in detail. The light-response characteristics of g-C3N4/NaTaO3/BM-C composites are effectively extended into the visible-light region. Compared with NaTaO3/BM-C and g-C3N4/NaTaO3, the g-C3N4/NaTaO3/BM-C composite showed high visible-light catalytic performance when the mass ratio of melamine (the g-C3N4 precursor) to binary NaTaO3/BM-C is 4:1, and the degradation extent of 95.85% for Rhodamine B can be reached in 60 min under visible-light irradiation. In addition, the photocatalytic mechanism showed that the enhanced photocatalytic activity of the composite may be attributed to the introduction of g-C3N4, which expanded the visible-light response range and the formation and effect of a good synergistic effect of BM-C and various components. This work provides useful insights for promoting the practical process of sodium tantalate photocatalytic materials.

A three-dimensional structure of ternary carbon for high performance supercapacitor

In supercapacitor applications, the energy storage capacitance and rate performance of graphene are severely weakened by the restacking of graphene sheets, which is a great challenge to overcome for fully exploring its supercapacitive properties. If one of the current strategies for promoting the ion diffusion of graphene is employed alone, only a limited improvement of supercapacitive performance of graphene can be achieved. Here, we combine three carbon allotropes into an all-carbon structure, and improve the ion diffusion and mitigate graphene restacking using combination of three strategies, including creating in-plane holes, self-assembling into three-dimensional (3D) structure, and adding spacers between graphene sheets. Thus a 3D hybrid-structured ternary-carbon (holey graphene/carbon nanotube/hollow carbon nano-onion, denoted as HG-CNT-HCNO) is synthesized as supercapacitor electrode material through a facile and effective one-step hydrothermal method. The synergistic effect of strategies and the different dimensional carbon allotropes endows the 3D structure with hierarchical porous structure, improved electron/ion transport, and increased energy storage sites. Consequently, the HG-CNT-HCNO exhibits high specific capacitance of 236.5 F g−1, ultrahigh rate capability (capacitance retention of 97.9% as the current density increases from 0.5 to 40 A g−1), and high electrochemical stability. Furthermore, the device with organic electrolyte shows high energy and power densities of 71.3 Wh kg−1 and 7.5 kW kg−1, respectively, demonstrating a high energy storage performance. The ternary-carbon structure may open up a new avenue for electrode performance optimization in the future energy storage systems by involving different dimensional carbon nanomaterials.

Fabrication of a ternary carbon dots/CoO/g‐C3N4 nanocomposite photocatalyst with enhanced visible‐light‐driven photocatalytic hydrogen production

AbstractBACKGROUNDPhotocatalytic hydrogen (H2) production using sunlight is a promising solution for obtaining clean renewable energy. Therefore, the study of efficient, nontoxic and stable photocatalysts is very important.RESULTSA novel ternary carbon dots/cobalt monoxide/graphitic carbon nitride (CDs/CoO/g‐C3N4) composite photocatalyst was prepared by a simple solvothermal method for photocatalytic H2 production under visible light irradiation (λ > 420 nm). Compared with single semiconductors CoO and g‐C3N4, and binary composite CoO/g‐C3N4, the ternary CDs/CoO/g‐C3N4 nanocomposite exhibited higher photocatalytic performance. The optimal photocatalytic H2 rate of CDs/CoO/g‐C3N4 photocatalyst was 987.4 μmol g−1·h−1 with the apparent quantum efficiency of 2.39% at 420 nm. This enhanced photocatalytic activity can be attributed to the synergy effect of strong absorption and electron buffer property of CDs as well as the merits of the internal heterojunction formed between CoO and g‐C3N4.CONCLUSIONSThis work provides a new approach to the design of a high‐efficiency composite photocatalyst for converting solar energy into chemical fuel. © 2020 Society of Chemical Industry