Hydrothermal Carbonization Of Glucose Research Articles

Direct oxidation of alcohols to carboxylic acids using simple and economical Pd@Glu-HTC catalyst: Practical and scalable approach towards biomass based value added chemicals

Sustainable catalytic transformation of bio-based alcohols to high value-added fine chemicals is an important topic of research. This work described preparation of simple and economical Pd@Glu-HTC catalyst from biomass derived low cost d-glucose. Hydrothermal carbonization of glucose was carried out in first step to synthesize Glu-HTC support in a simpler, greener, economical and efficient manner followed by incorporation of palladium metal on surface of the catalyst in second step. The catalyst was characterized using techniques such as Fourier Transform Infrared Spectroscopy (FT-IR), Solid-state Cross-Polarization Magic Angle Spinning Carbon-13 (13C CPMAS), Energy-dispersive X-ray spectroscopy (EDAX), Powder X-ray diffraction (P-XRD), X-ray photoelectron spectroscopy (XPS), Thermogravimetric/Differential Thermal Analyzer (TG-DTA), Field emission scanning electron microscopy (FE-SEM) and High-resolution transmission electron microscopy (HR-TEM). The catalyst was evaluated for direct oxidation of alcohols to yield carboxylic acids and exhibited very good catalytic activity for wider substrate scope. Oxidation of alcohols was carried out using milder base, molecular oxygen and water as a solvent to achieve 92–99 % excellent yields. The practical utility of current strategy was also studied for gram scale synthesis of bio-based value added industrially important chemicals such as furoic acid (flavouring agent and preservative in industry), 2, 5-furan-dicarboxylic acid (monomer to 100 % fossil-free, recyclable polymer polyethylene furanoate (PEF), tetrahydro-2-furoic acid (production of many drugs) and vanillin (important product of flavor and fragrance industry). Pd@Glu-HTC catalyst was found to be reusable for four recycles and the catalytic performance was retained without any loss in its activity after four cycles.

Scavenging of DPPH by Persistent Free Radicals in Carbonized Particles

AbstractPersistent free radicals (PFR) in carbonized particles may play a role in degradation of environmental compounds. The influence of PFR is evaluated in various carbonized particles on their radical scavenging efficiency upon the common radical indicator 2‐2‐diphenyl‐1‐picrylhydrazyl (DPPH). Carbonized particles are derived by hydrothermal carbonization of glucose (C‐W) or glucose and urea (NC‐W) and ionothermal carbonization of glucose and urea ionic liquid (IL) (NC‐IL). The carbonized materials contain OH/COOH, C=C, and C‐O functionalities. The addition of urea introduces NH/NH2 functionalities. The content of polar surface groups is lower in IL‐processed NC‐IL. The scavenging ability, measured as DPPH UV–vis absorption decline, increases with concentration and time for all particles, while the efficiency changes are in the order of C‐W > NC‐W > NC‐IL. Electron paramagnetic resonance analysis reveals similar radical concentration in all carbonized materials studied. The difference in efficiency is, thus, not directly related to the PFR concentration but rather to the type of PFR, surface functionalities and/or scavenging mechanism. According to the g‐values, radicals in these particles are carbon‐centered. The minor variation in g‐values suggests interactions between the radicals and their environmental functional groups. This provides insights into the influence of PFR in carbonized materials on their radical scavenging efficiency.

Hydrothermal carbonization of glucose: Secondary char properties, reaction pathways, and kinetics

Hydrothermal carbonization (HTC) is a promising green route to synthesize carbon materials and valorize biomass waste. The intricacy behind the conversion is enormous, requiring investigations of the mechanisms starting from the fundamentals. Intending to contribute to the rudiments of HTC, this work provides a systematic insight into the decomposition of glucose during HTC. The interest in glucose stems from its nature, indeed it is: one of the building blocks of biomass, a substrate for producing advanced carbon materials, and a precursor of secondary char - the solid phase deriving from re-polymerization and condensation reactions from the liquid phase back onto solid. The work approaches the glucose HTC holistically, focusing on kinetics and characterization of the products. A 1.1 M glucose solution was hydrothermally carbonized over several operating conditions (180–270 °C and 0–8 h) with analysis of the solid and liquid phases. Results show that hydrochar changes significantly with time only at 180 °C. Above 180 °C, the solid yield stabilizes at 47–50 % and the carbon content at 67–70 %. The time-evolution of liquid intermediates (like HMF and small carboxylic acids) detected through NMR enabled the deduction of formation pathways and calibration of a higher-order kinetics model. Meanwhile, SEM and Raman spectra show hydrochars characterized by typical nano/microspheres, having a size distribution dependent on operating conditions and mainly an amorphous structure, with a tendency towards graphitization as the HTC severity increases. All the hydrochars show photoluminescence, a functionality that opens to several application possibilities.

Magnetic hydrothermal carbonaceous nanospheres bonded cell membranes as a stable and reusable platform for discovering natural bioactive components

The covalent bionic modifications of hydrothermal carbonaceous nanomaterials (HCNs) are of great potential in extraction and separation engineering because they can avoid present disadvantages of chemical functionalization and achieve selective recognition capacity with stability and sustainability. This article developed novel dual functionalized HCNs with sealed magnetic nanospheres (MNs) and cell membranes (CMs) of osteoblast, via the hydrothermal carbonization of glucose on MN surface and the aqueous amidation between terminal amino groups on CMs and surface carboxyl groups on HCNs. Owing to the specific combinations between drugs and membrane receptors, CMs bonded magnetic HCNs (CM-MHCNs) were applied as a drug discovery platform to screen potential anti-osteoporosis components from traditional herb medicine. The introduction of hydrothermal carbonaceous layer on MNs was proved to sharply improve their water dispersibility, resistance to oxidation and acids and CM grafting capacity with good magnetic property. These combined with the covalent bonding between prepared MHCNs and CMs provided the enhanced stability, where the loss amount (7.0 mg g−1) was dramatically reduced in comparison with that of CMs adsorbed MHCNs (17.9 mg g−1) and MNs (18.7 mg g−1). The resultant CM-MHCNs showed high adsorption ability, rapid binding kinetics, good selectivity and reusability. Consequently, two novel potential anti-osteoporosis compounds: isopimpinellin and xanthotoxol were successfully discovered from Common Cnidium Fruit, which were confirmed by pharmacodynamic experiments. Their possible membrane receptors were further investigated by molecular docking and western blot analysis. These researches on CM-MHCNs offer a deep insight into green design of stable biomaterials and show their promising prospect in the discovery of drug leads, thus promoting the development of traditional herb medicines.

N, S co-doped carbon spheres synthesized from glucose and thiourea as efficient CO2 adsorbents

BackgroundSynthesis of N, S co-doped carbon has been actively pursued due to their wide applications in different fields including CO2 adsorption. MethodsIn the current work, spherical hydrochar was obtained from the hydrothermal carbonization of glucose. The hydrochar was then conveniently converted into N, S co-doped carbon sphere by KHCO3 activation in the presence of thiourea. Significant findingsThe carbon spheres were successfully doped with high contents of nitrogen (4.8–13.0 wt%) and sulfur (2.4–5.6 wt%). The carbon spheres demonstrated specific surface area as high as 2581 m2/g. Influences of various physicochemical properties on CO2 uptake, adsorption heat, CO2/N2 adsorption selectivity were studied and analyzed. CO2 uptake of 3.4 mmol/g at 25 °C and 1 bar was achieved by the carbon spheres. The results also showed that CO2 uptake was mainly decided by volume of small micropores. Nitrogen doping showed positive effects on improving CO2 uptake and adsorption selectivity, while sulfur doping significantly enhanced interaction strength and improved the adsorption heat. The current work demonstrated a convenient synthesis strategy of N, S co-doped carbonaceous CO2 adsorbents with controlled morphology. We hope this work will provide new insights into the synthesis and application of heteroatom doped carbons.

Blue hydrochars formed on hydrothermal carbonization of glucose using an iron catalyst

We hypothesized that the morphology of the hydrochar from hydrothermal carbonization of glucose would be affected by Fe2+; and indeed, with such ions, large pieces of hydrochar formed that comprised aggregated spherical particles and blue and thin films. Thin carbonized films formed at the bottom of the autoclave liners or on TeflonTM tape used as a template. Free-standing films could be prepared by stretching the TeflonTM tape after the synthesis. The carbonized films that formed at the bottom of the autoclave adhered to spherical hydrochar particles. The blueness was ascribed to thin-film interference under white-light irradiation and related to the film thickness, which was about 200 nm. Analysis of transmission electron microscopy (TEM) images showed that the films consisted of a layered amorphous carbon. The amorphous and thin films were more carbonized than the amorphous carbon of the TEM grid, as derived via electron energy loss spectroscopy (EELS). Additional analysis of one of the thin films by X-ray photoelectron spectral analysis showed a higher carbon fraction than for bulk hydrochar, supporting the EELS analysis. We believe that the synthesis of thin films of hydrochar can open up new colloidal processing pathways, which could be useful in the preparation of carbon-based materials and alike.

Line Patterns and Fractured Coatings in Deposited Colloidal Hydrochar on Glass Substrates after Evaporation of Water

Patterns of assembled colloidal particles can form on substrates due to solvent evaporation, and here we studied such phenomena in the drying of monodispersed colloidal hydrochar dispersions prepared by the hydrothermal carbonization of glucose and purified by dialysis. During the evaporation of water, line patterns or, in some cases, mud-like patterns formed. The line formation was investigated as a function of the pH of the dispersion, substrate shape, particle concentration, and concentration of sodium dodecylsulfate (SDS). The lines comprised dense assemblies of hydrochar particles. The line width increased with the successive evaporation of water. Sharper lines formed with the addition of SDS, which was ascribed to the effects of solubilization or moderated interactions. At greater particle concentrations, we also observed a continuous layer of colloidal particles between the lines. A mechanism for the line pattern formation derived from the literature on other colloids was proposed. Mud-like patterns formed on the substrate in concentrated samples without SDS addition and were put in the context of the formation of cracks in the drying of colloidal coatings. Hydrochars belong to carbon-rich colloids, which are of fundamental and technological importance. This research could be useful for in situ line printing within microfluidic devices, for example.

Modulated photoluminescence and photodynamic efficiency of hydroxyapatite-methylene blue@carbon-ions by ion-π coupling interactions

As a noninvasive methodology, image-guided photodynamic therapy is promising to treat diseases without inducing drug resistance with chemotherpy in clinical applications. The photo-related properties of methylene blue (MB) as flurophore/photosensitizer are closely related with energy and charge transformations in multifunctional drug delivery systems. Herein, MB monomers are combined by citrate- and β-cyclodexin-modified hydroxyapatite (HAp) with ions-doped carbon shells prepared by hydrothermal carbonization of glucose. Photoluminescence and photodynamic efficiency are tuned by ion-π coupling interactions between ions (M) and MB molecules in HAp-MB@C-M. With increased addition of Zn2+ ions during carbonization, narrowed absorbance peaks to low excitonic band without additional decay channels are observed for HAp-MB@C-Zn with increased emission intensities. As energy decay pathways, ring vibrations of MB are quite weak with small infrared peaks for these fluorochromes with increased luminescence emissions. High oscillate strength contributes to the increased generation efficiency of singlet oxygen for MB released from HAp-MB@C-Zn. The present studies would shed light on the modulations of aggregation states of photosensitizers and their photo-related properties of luminescence emission and therapy efficiency to meet the simultaneous requirements of image-guided photodynamic therapy.

A solar-driven photoelectrochemical platform based on Ag-sensitized TiO2 NTAs for pollutant treatment and hydrogen generation

Nanofunctional photocatalysts are attractive materials in solar energy transformation for environmental protection and green energy source generation. TiO2 nanoparticles are the most prospective photocatalysts due to the high photoactive property. In this paper, Ag nanoparticle-sensitized TiO2 nanotube arrays (Ag/TiO2 NTAs) were constructed as the photoelectrochemical platform for pollutant removal and hydrogen generation. TiO2 NTAs were firstly obtained by the anodization method, and carbon layer was formed by the hydrothermal carbonization of glucose in different concentrations, and then Ag nanoparticles were deposited by carbon reduction of Ag+. Ag/TiO2 NTAs could effectively decompose organic dye molecules and remove toxic heavy metal ions. The samples also could achieve visible light photocurrent and hydrogen generation. The surface plasmon resonance absorption and electron transfer path of Ag nanoparticles benefit photochemical performance improvement of TiO2 NTAs. The construction of multifunctional platform of Ag/TiO2 NTAs would cause extensive response and focus in the synergistic applications of semiconductor photocatalysts.

Macroscopic rods from assembled colloidal particles of hydrothermally carbonized glucose and their use as templates for silicon carbide and tricopper silicide

Self-aggregated colloids can be used for the preparation of materials, and we studied long rod-like aggregates formed on the evaporation of water from dispersed particles of colloidal hydrochar. The monodispersed hydrochar particles (100–200 nm) were synthesized by the hydrothermal carbonization of glucose and purified through dialysis. During the synthesis they formed colloidal dispersions which were electrostatically stable at intermediate to high pH and at low ion strengths. On the evaporation of water, macroscopically large rods formed from the dispersions at intermediate pH conditions. The rods formed at the solid-water interface orthogonally oriented with respect to the drying direction. Pyrolysis rendered the rods highly porous without qualitatively affecting their shape. A Cu-Si alloy was reactively infiltrated into the in-situ pyrolyzed hydrochars and composites of tricopper silicide (Cu3Si)-silicon carbide (SiC)/carbon formed. During this process, the Si atoms reacted with the C atoms, which in turned caused the alloy to wet and further react with the carbon. The shape of the underlying carbon template was maintained during the reactions, and the formed composite preparation was subsequently calcined into a Cu3Si-SiC-based replica of the rod-like assemblies of carbon-based colloidal particles. Transmission and scanning electron microscopy, and X-ray diffraction were used to study the shape, composition, and structure of the formed solids. Further studies of materials prepared with reactive infiltration of alloys into self-aggregated and carbon-based solids can be justified from a perspective of colloidal science, as well as the explorative use of hydrochar prepared from real biomass, exploration of the compositional space in relation to the reactive infiltration, and applications of the materials in catalysis.

Amino-functional biocarbon with CO2-responsive property for removing copper(II) ions from aqueous solutions

Amino-functional biocarbons (NH3-HTC, FA-HTC) were synthesized by one-pot hydrothermal carbonization of glucose (HTC) using ammonia (NH3) or ammonium formate (FA) additives. The as-prepared amino-functional biocarbons had specific surface areas of (5 to 8) m2/g, amino- content of (4 to 5) mmol/g, COOH content of (2 to 4) mmol/g and OH content of about 1 mmol/g. Experiments at 20 °C revealed that the as-prepared amino functional biocarbons NH3-HTC and FA-HTC, had copper (II) ion adsorption capacities of 182 mg/g and 265 mg/g over a 60 min period and approached 90 % saturation within 15 min. Adsorption isotherms of NH3-HTC could be described by the Freundlich model (R2> 0.95) and thermodynamic parameters of NH3-HTC showed that copper (II) adsorption was mainly physical adsorption. X-ray photo-electron spectroscopy (XPS) and Fourier transform infrared (FT-IR) spectroscopy of biocarbon adsorbents revealed that both amino groups and oxygen groups of the biocarbon adsorbent are involved in the copper (II) ion adsorption mechanism. Biocarbon adsorbents could be regenerated with 0.1 M nitric acid, 0.1 M organic acids (oxalic, citric), or CO2 bubbling. Amino-functional biocarbons are simple to prepare from biomass-derived compounds, they have high affinity for metal ions and they can be regenerated with environmentally-safe methods.

Phosphorus-doped carbon/carbon nanotube hybrids as high-performance electrodes for supercapacitors

P-doped carbon hybrids were prepared by hydrothermal carbonization of glucose in the presence of CNT followed by chemical activation with phosphoric acid. The role played by phosphoric acid on the final textural and chemical properties of the samples was thoroughly investigated by varying the temperature of activation. Temperatures higher than 700°C were needed to chemically activate the samples, while 800°C is the optimum temperature to generate the largest amount of micropores. In addition to oxygen functional groups such as carboxylic acids, anhydrides, lactones, phenols and carbonyl quinones, several phosphorus functional groups are also detected. At 700°C, only COPO3 and CPO3 groups are observed; meanwhile, C3P=O and C3P groups appear at 800 °C and 900 °C, respectively. The oxygen moieties bonded to carbon and the phosphates (COPO3) contribute significantly to the pseudocapacitance; the oxygen groups linked to phosphorus (CPO3 and C3P=O) enhance the electrostatic charge and the non-oxygen functional group (C3P) increases the capacitance retention. The P-doped hybrid treated at 800 °C resulted in a porous carbon material with 806 m2 g−1 active surface area and high phosphorus content (6.6%) that increases the total capacitance from 26 (non-doped hybrid treated at 700°C) to 124 F g−1 at 1 A g−1. Besides, its high content of phosphorus increases the rate capability (115 F g−1 at 10 A g−1), resulting in an electrode material with higher performance at large current density than that of commercial activated carbon Supra50.

Novel 4ZnO⋅B2O3⋅H2O:Ln3+/HTC (where Ln = Eu or Tb) phosphors: Synthesis, morphology and luminescence properties

Abstract

Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

Abstract Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes (CNTs) were functionalized with melamine and/or iron(II) phthalocyanine (FePc) following three different methodologies: (i) Functionalization with melamine via thermal treatment, (ii) incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and (iii) functionalization with melamine followed by FePc incorporation. The chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction (ORR). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. Regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFePc surpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products (

Hydrothermal Carbon‐Doped Polyethylene Glycol as Phase‐Change Materials with Good Thermal Conductivity and Shape‐Stability

AbstractPolyethylene glycol (PEG) is limited by the low thermal‐conductivity and poor shape‐stability in practical applications. In our work, the thermal conductivity and shape‐stable phase change Materials (SSPCMs) doped with hydrothermal carbon (HTC) was successfully prepared. HTC with ‐ OH and ‐ COOH groups on the surface was prepared by hydrothermal carbonization of glucose. The hydrogen bonds were formed between functional groups on HTC surface and PEG to obtain the network structure. When the HTC doping ratio is 6 wt%, good shape‐stability can be achieved. Besides, the thermal conductivity of the HTC/PEG SSPCMs with the HTC doping ratio of 9 wt% is 0.6121 W/(m⋅K), which is 134.7% higher than PEG. The DSC results show that the melting enthalpy (ΔHm) of PEG and HTC/PEG SSPCMs is almost the same, as is the crystallization enthalpy (ΔHc). It indicates that doping HTC does not substantially affect the heat storage capacity of PEG.

Formation of Soluble Furanic and Carbocyclic Oxy-Organics during the Hydrothermal Carbonization of Glucose

In this study, the water-soluble products formed during the hydrothermal carbonization of glucose were analyzed by liquid chromatography (LC)–mass spectrometry (MS) and LC–MS2 to determine the formulas and the possible structures of the main compounds. In addition to the well-known compounds of 3-deoxyglucosone, 5-hydroxymethylfurfural, and levulinic acid, the furanic compounds and the carbocyclic oxy-organics containing hydroxy group and carbonyl group with a molecular mass range between 170 and 260 Da were also identified. Both C–C coupling reaction and C–C cleavage reaction were proved to be involved during the formation of these carbocyclic oxy-organics, so they were proposed to be released via C–C cleavage of the primary polymers, which were formed by aldol condensation of the primary precursors formed during the degradation of glucose. The identification of these carbocyclic oxy-organics was indirect evidence that aldol condensation played a crucial role during the formation of hydrochar from carbonization of glucose.

Effects of Acidic and Alkaline Metal Triflates on the Hydrothermal Carbonization of Glucose and Cellulose

The transformation of glucose and cellulose into carbon-rich solid materials was carried out in hydrothermal media at 200 °C for 48 h with and without the use of acidic (Al(OTf)3) and alkaline (NaOTf) catalysts. The effects of the catalyst type on the yield of hydrothermal carbons (HTCs) and their properties were investigated. The use of Al(OTf)3 led to a decrease in the yields of HTCs for both feedstocks. This result was reversed for the runs with NaOTf. Glucose-derived solid product without the use of a catalyst produced carbon spheres of a diameter between 500 and 600 nm. The use of a catalyst (regardless of whether Al(OTf)3 or NaOTf) produced larger particles. Scanning electron microscopy images of HTC from cellulose exhibited irregular morphology. Carbon spheres produced from cellulose without the use of a catalyst ranged between 200 nm and 2 μm. HTC products from cellulose with Al(OTf)3 yielded aggregated carbon spheres with a diameter ranging between 300 and 600 nm. The use of NaOTf inhibited the s...

High-efficiency electrogeneration of hydrogen peroxide from oxygen reduction by carbon xerogels derived from glucose

Developing highly active and selective, and low cost electrocatalysts for the 2e− oxygen reduction from environmentally friendly precursors is attractive to industrial production and environmental remediation. In this study, carbon xerogels (CXs) were synthesized by the hydrothermal carbonization of glucose and polyaniline (PANI) and then used as catalysts for electrochemical generation of H2O2 from O2. It was found that the H2O2 production performance could be easily tunable by polymerization temperature of PANI (0–80 °C), in which onset potential (−0.45 V to −0.29 V) decreased while the catalytic activity and H2O2 selectivity (47%–94%) increased with the polymerization temperature. CX-80 (prepared at 80 °C) exhibited the best catalytic activity with excellent H2O2 selectivity of 94% in neutral condition, better than most reported electrocatalysts. The H2O2 production was also tested using gas diffusion electrodes modified by CXs, showing a high H2O2 yield (5.1 mg h−1 cm−2) and stability with low energy consumption (7.2 kWh kg−1) at cathode potential of −1.0 V and pH 7. The excellent performance of CX-80 was attributed to large volume of meso-/macropores and high content of C=O. We believed that CX-80 would be a promising metal-free electrocatalyst for sustainable and in-situ H2O2 generation from O2 in energy and environmental fields.

Glucose-derived carbon materials with tailored properties as electrocatalysts for the oxygen reduction reaction.

Nitrogen-doped biomass-derived carbon materials were prepared by hydrothermal carbonization of glucose, and their textural and chemical properties were subsequently tailored to achieve materials with enhanced electrochemical performance towards the oxygen reduction reaction. Carbonization and physical activation were applied to modify the textural properties, while nitrogen functionalities were incorporated via different N-doping methodologies (ball milling and conventional methods) using melamine. A direct relationship between the microporosity of the activated carbons and the limiting current density was found, with the increase of microporosity leading to interesting improvements of the limiting current density. Regardless of the doping method used, similar amounts of nitrogen were incorporated into the carbon structures. However, significant differences were observed in the nitrogen functionalities according to the doping method applied: ball milling appeared to originate preferentially quaternary and oxidized nitrogen groups, while the formation of pyridinic and pyrrolic groups was favoured by conventional doping. The onset potential was improved and the two-electron mechanism of the original activated sample was shifted closer to a four-electron pathway due to the presence of nitrogen. Interestingly, the high pyridinic content related to a high ratio of pyridinic/quaternary nitrogen results in an increase of the onset potential, while a decrease in the quaternary/pyrrolic nitrogen ratio favors an increase in the number of electrons. Accordingly, the electrocatalyst with the highest performance was obtained from the activated sample doped with nitrogen by the conventional method, which combined the most appropriate textural and chemical properties: high microporosity and adequate proportion of the nitrogen functionalities.

Influence of Multiwalled Carbon Nanotubes as Additives in Biomass-Derived Carbons for Supercapacitor Applications.

Glucose-derived carbon/carbon nanotube (CNT) hybrid materials were prepared by hydrothermal carbonization of glucose in the presence of CNTs and subsequent carbonization, physical activation, or chemical activation. The proportion of CNTs added during the hydrothermal polymerization of glucose was varied to ascertain the optimum dose to maximize the performance of the carbon hybrids in supercapacitor applications. Both the thermal treatment applied and the addition of CNTs lead to changes in the textural and chemical properties of the activated carbons. It was observed that samples bearing CNTs exhibit higher number of nucleation centers for glucose oligomers to polymerize, and consequently, the behavior of the hydrothermal carbon toward activation differs according to the activating agent employed. Moreover, the initial chemical speciation dominated by acidic groups shifts to more basic functionalities (quinones and carbonyl groups) with the addition of CNTs. The effect of the different physicochemical properties of the prepared carbons on their electrochemical behavior was evaluated. The addition of 2 wt % of CNTs and subsequent chemical activation leads to electrode materials yielding 206 F g-1 and 78% of capacitance retention up to 0.8 V and 20 A g-1 and high rate cyclability (97% after 5000 cycles). The outstanding performance is ascribed to the high surface area, narrow mesopores, and phenol/carbonyl surface functionalities, which enhance molecular diffusion, the amount of stored energy, and electronic transportation, respectively.