Smaller Specific Surface Area Research Articles

Hydrogen peroxide electrosynthesis using commercial carbon blacks as catalysts: the influence of surface properties and adsorption performance

AbstractBACKGROUNDSurface properties and adsorption performance of carbon materials play a crucial role in the electrochemical two‐electron oxygen reduction to produce H2O2. However, there is still a lack of in‐depth research on commercial carbon blacks in this area. Herein, four typical commercial carbon blacks (Acetylene black (AB), Ketjen black EC 600JD, Vulcan XC 72 and Black Pearls 2000) were used as cathode catalysts to generate H2O2. Surface chemistry and pore structure of electrodes of the four carbon blacks were systematically characterized, and their effects on H2O2 adsorption, electrochemical generation and degradation were investigated.RESULTSAmong the four carbon blacks, AB has the highest content of C–O–C/COOH and CO, which are active groups catalyzing the two‐electron oxygen reduction reaction to generate H2O2. AB has the lowest level of defects and highest degree of graphitization, and AB‐modified graphite felt electrode (AB‐Ele) has the largest average pore diameter, smallest specific surface area and smaller charge transfer resistance. H2O2 production using AB‐Ele is the largest and reaches 567.7 mg L−1 at 180 min under a current density of 5 mA cm−2, and only decreases by 17.6% after 10 repeated uses.CONCLUSIONOverall, rich oxygen‐containing functional groups such as C–O–C, COOH and CO, high degree of graphitization, suitable surface area and porosity as well as weak H2O2 adsorption performance are beneficial for the two‐electron oxygen reduction reaction to generate H2O2. AB‐modified graphite felt electrode exhibits good catalytic activity and reusability in H2O2 electrosynthesis, demonstrating promising application prospects. © 2024 Society of Chemical Industry (SCI).

Influence of shale reservoir properties on shale oil mobility and its mechanism

Given the tremendous potential for continental shale oil in China, many oilfields in the central and eastern parts of the country are involved in the exploration and development of shale oil resources. Besides engineering factors, shale oil mobility is the key to determining its commercial viability. This study explores the Hetaoyuan Formation in the Biyang Depression as an example to determine the influence of reservoir properties on the movable oil volume and its mechanisms. Multiple techniques were used, including displacement nuclear magnetic resonance (NMR), low-temperature nitrogen adsorption (LTNA), X-ray diffraction (XRD) bulk mineral analysis, and scanning electron microscopy (SEM), and the results suggest that large average pore diameter, high throat to pore ratio, single pore morphology, and small specific surface area can weaken the boundary layer effect and reduce the amount of adsorbed oil. Our observations reveal that compared to the dissolution pores and intergranular pores in brittle minerals, the intercrystalline pores in terrigenous clastic clay minerals are more affected by compaction. Furthermore, authigenic clay minerals notably block the intergranular pores in the interbedded sandstones. Clay minerals are identified as the main contributor to the specific surface area, with high clay mineral content enhancing the pore heterogeneity of the reservoir. Thus, positive shale oil mobility occurs in shale with a weak boundary layer effect, which is attributed to the high brittle mineral content, large average pore diameter, small specific surface area, single pore morphology, and reservoir homogeneity.

Unraveling the relationship between the mineralogical characteristics and lithium storage performance of natural graphite anode materials

Anode materials play critical role in cycling life of lithium-ion batteries in practical applications such as electric vehicles (EVs), portable electronic devices, and large-scale power grids. Natural graphite is one of the most successful anodes for commercial lithium-ion batteries due to its high theoretical capacity and low cost and low operating voltage. The mineralogical properties of graphite minerals have an important effect on the electrochemical performance of graphite anode, while their relationship remains ambiguous. In this work, natural graphite samples from four main graphite mining areas in China were selected as the research object, and their mineralogical characteristics were characterized by XRD, SEM, Raman, ICP, SEM, FIB, BET and other test methods. The properties of crystallinity, morphology, surface/phase defects, impurities, and specific surface area of graphite were studied. The results show that the cyclic stability of graphite is mainly affected by bulk defects and crystallinity, and the initial coulombic efficiency is mainly affected by surface defects and specific surface area. Graphite samples with appropriate surface defects, fewer volume defects, appropriate crystallinity, and small specific surface area have better electrochemical performance. It is hoped that this work should guide the manufacture and modification of the natural graphite anodes and promote its wider application in lithium-ion batteries.

Solid-state lithium batteries composed of hematite and oxide electrolyte

As Li-ion battery anode materials, two types of hematite (Fe2O3(big), Fe2O3(ultrafine)) were evaluated by using liquid electrolyte and oxide-based solid electrolyte. Although the anode using Fe2O3(ultrafine) with larger specific surface area showed a high initial reversible capacity in the liquid-electrolyte cell, there was a steep capacity decay in the cycling test. In the solid-electrolyte cell, we obtained very low reversible capacities of 40 mA h g−1 for the anode using Fe2O3(big) with smaller specific surface area. In contrast, the capacity of Fe2O3(ultrafine) anode was as high as 400 mA h g−1 at the 20th cycle. This is the first demonstration of charge–discharge reactions for Fe2O3 anode in oxide-based solid-state batteries. The Fe2O3(ultrafine) particles were dispersed relatively uniformly between solid electrolyte in the active layer, suggesting that the contact area between Fe2O3 and solid electrolyte becomes large. Consequently, Fe2O3(ultrafine) could benefit from larger contact area delivering the suitable reaction site for Li+ to improve the anode performance.

Constructing Efficient CuO-Based CO Oxidation Catalysts with Large Specific Surface Area Mesoporous CeO2 Nanosphere Support.

CeO2 is an outstanding support commonly used for the CuO-based CO oxidation catalysts due to its excellent redox property and oxygen storage-release property. However, the inherently small specific surface area of CeO2 support restricts the further enhancement of its catalytic performance. In this work, the novel mesoporous CeO2 nanosphere with a large specific surface area (~190.4 m2/g) was facilely synthesized by the improved hydrothermal method. The large specific surface area of mesoporous CeO2 nanosphere could be successfully maintained even at high temperatures up to 500 °C, exhibiting excellent thermal stability. Then, a series of CuO-based CO oxidation catalysts were prepared with the mesoporous CeO2 nanosphere as the support. The large surface area of the mesoporous CeO2 nanosphere support could greatly promote the dispersion of CuO active sites. The effects of the CuO loading amount, the calcination temperature, mesostructure, and redox property on the performances of CO oxidation were systematically investigated. It was found that high Cu+ concentration and lattice oxygen content in mesoporous CuO/CeO2 nanosphere catalysts greatly contributed to enhancing the performances of CO oxidation. Therefore, the present mesoporous CeO2 nanosphere with its large specific surface area was considered a promising support for advanced CO oxidation and even other industrial catalysts.

Transient electrophoresis of a conducting cylindrical colloidal particle suspended in a Brinkman medium

The time-dependent electrophoresis of an infinitely cylindrical particle in an electrolyte solution, saturated in a charged porous medium after the sudden application of a transverse or tangential step electric field, is investigated semi-theoretically with an arbitrary double-layer thickness in an arbitrary direction relative to the cylinder. The time-dependent modified Brinkman equation with an electric force term, which governs the fluid flow field, is used to model the porous medium and is solved by using the Laplace transform technique. Explicit formulas, for the time-dependent electrophoretic velocity of the cylindrical particle in Laplace’s transform domain, have been derived for both axially and transversely when the uniform electric fields are imposed. They can also be linearly superimposed for an arbitrarily oriented relative to the electric field. Semi-analytical results for the electrophoretic velocities are presented as functions of the dimensionless elapsed time, the ratio of the particle radius to the Debye length, the particle-to-medium density ratio, and the permeability parameter of the porous medium. The results demonstrate, in general, that the growth of the electrophoretic velocities with the time scale are more slower for high permeability, and the effect of the relaxation time for unsteady electrophoresis is found to be negligible, regardless of the thickness of the double layer, the relative mass density or the permeability of the medium. The normalized transient electrophoretic velocities exhibit a consistent upward trend as the ratio of the particle radius to the Debye screening length increases. Conversely, they display a consistent downward trend as the particle-to-fluid density ratio increases, while all other parameters remain constant. The effect of the relaxation time for the transient electrophoresis is much more important for a cylindrical particle than for a spherical particle due to its smaller specific surface area.

Salt-Supported Nickel Oxides for Boosted Hydrogen Production: The Critical Role of Halogen.

Hydrogen production from organic waste by gasification and reforming technologies offers major benefits to both the environment and climate. The long-term stability and regeneration of the reforming catalyst are still the biggest challenges because of carbon deposition. Here we report a recyclable salt-supported nickel oxide NiO/NaX (X: F, Cl, Br) catalyst for effective autothermal reforming of the oxygenated volatile organic compound (OVOC) ethyl acetate to hydrogen. The optimal hydrogen selectivity achieved 82.0% at 650 °C and the durability reached 43 h. Interestingly, with the decreasing of halogen electronegativity (F > Cl > Br) in NaX, the corresponding hydrogen selectivity of the catalysts decreased. Although NiO/NaX catalysts possess a very small specific surface area and a dense microstructure, their catalytic performance is better than that of normal Ni-based catalysts loaded on high-specific-surface-area supports. Detailed investigations revealed the critical roles played by halogen during the reforming reaction. First, the strong electronegative halogen in NaX induced the formation of hydrogen bonds with the reactants and reaction intermediates, which may prolong the surface residence time of such species, thus ensuring efficient hydrogen production over small-specific-surface-area catalysts under high-temperature conditions. Second, the halogen of the support NaX weakening the Ni-O bonds of the exposed Ni atoms in NiO/NaX made it easier for NiO to be reduced to Ni0, thus reducing the reaction activation energy and prompting the rapid catalytic reaction. The strength of such metal-support interaction can be easily modulated by varying the halogen electronegativity. This study provides a new prospect for the design of innovative recyclable heterogeneous catalysts with low specific surface area but high activity.

High‐Coulombic‐Efficiency Hard Carbon Anode Material for Practical Potassium‐Ion Batteries

AbstractBiomass‐derived hard carbon (HC) has emerged as a promising candidate for anode materials of potassium‐ion batteries because of low cost and abundant raw materials. Whereas, the large specific surface area and high porosity of this type of HC often lead to inferior initial Coulombic efficiency (ICE) and unsatisfactory cycling stability. Herein, we report a coconut shell‐derived HC (CS‐HC) featuring an expanded interlayer spacing and small specific surface area. The CS‐HC delivers a reversible specific capacity of 280 mAh g−1 and an impressive ICE of 87.32 % at 50 mA g−1. In addition, it exhibits stable cycling performance (92.8 % capacity retention after 100 cycles at 50 mA g−1) and fast rate capability (∼280 mAh g−1 at 300 mA g−1). The ex situ Raman spectra characterization combined with cyclic voltammetry tests elucidate that the storage of potassium ions in the present HC is mainly achieved by (pseudo)capacitive behavior at the disordered defect sites along with minor contribution from the interlayer intercalation process. Finally, a full‐cell constructed with unprecycled CS‐HC anode and high‐voltage K2Mn[Fe(CN)]6 cathode demonstrates exceptional electrochemical stability and retains 90.6 % capacity after 100 cycles. This work reports a high‐performance HC anode material derived from low‐cost and sustainable biomass for practical potassium‐ion batteries.

Porous Carbon Cloth@CoSe2 as Kinetics‐Enhanced and High‐Loading Integrated Sulfur Host for Lithium–Sulfur Batteries

AbstractCarbon cloth (CC) possesses great potential as a sulfur host because of its excellent conductivity, flexibility, and easily modified free‐standing structure. However, the previous works do not take full advantage of CC except for the role of support and current collector. The smooth surface, small specific surface area, and poor binding force between coating materials and CC matrix are unfavorable for loading coating materials. The slow redox kinetics and low sulfur loading of sulfur cathodes still seriously restrict the development of Lithium–Sulfur (Li–S) batteries. Herein, the porous carbon cloth loading cobalt selenide (PCC@CoSe2) is constructed as an integrated sulfur host through a pore‐creating and selenylation strategy. The pore‐creating engineering greatly optimizes the 3D pore structure of CC to raise the sulfur and catalyst loading and provides enough space to accommodate the volume change of sulfur species. In addition, CoSe2 particles as nano‐catalyst units embedded in PCC can effectively adsorb‐catalyze polysulfides and improve the reaction kinetics. The resulting integrated sulfur cathode has realized the high‐efficiency polysulfide catalytic conversion and fast lithium ion migration, significantly enhancing redox kinetics and sulfur loading.

High-performance plastic-derived metal-free catalysts for organic pollutants degradation via Fenton-like reaction

The preparation of waste plastics-derived catalysts is an effective strategy for the waste reclamation. However, plastic-derived material is unsuitable for wastewater purification due to its small specific surface area (SSA) and inadequate active sites (such as N/O sites). Herein, we synthesized graphene-like nanosheets using g-C3N4 as the self-sacrificing soft template and plastic as the carbon precursor. Consequently, this strategy greatly promoted the efficiencies of the emerging organic pollutants degradation with the SSA and N content of the plastic-derived biochar increasing up to 1043.4 m2/g and 17.53 at.%, respectively. In detail, 100 % sulfadiazine (SD) removal could be achieved in 180 s via the activation of peroxymonosulfate (PMS) and the catalytic activity is far higher than previous research. Mechanism experiments corroborated that such a striking performance was attributed to the generation of SO4•−, O2•− and 1O2. Meanwhile, kinds of plastic precursors, even medical waste (i.e., masks, gauze, operating caps and degreasing cotton) were also applicable. And the practical application of the plastic-derived catalyst was further demonstrated by treating pollutants in a continuous flow mode with in situ fabricated membrane. This work provides valuable insights into waste plastics processing and water pollutants removal.

High-performance rechargeable aqueous zinc-iodine batteries via a dual strategy of microporous carbon nanotubes for cathodic iodine immobilization and modified separator

Compared with lithium-ion battery, aqueous rechargeable zinc-iodine is of interest due to their high safety and low cost. Unfortunately, the host material's low conductivity, small specific surface area, shuttling effect, and high soluble iodine species (I2, I-, and I3-) are inhibiting its wide development. In this work, a dual strategy of fixing iodine active material with nanotubular microporous carbon (MCN) and modified cotton fiber separator (MCN@CF) is employed to solve the above-mentioned problem. The Zinc-ion batteries (ZIBs) assembled with an MCN/I2 cathode and MCN@CF separator show up to 162 mA h g-1 of reversible initial capacity with 85 % capacity retention at 100 mA g-1 after 100 cycles. Moreover, besides featuring excellent long-term cyclability, MCN@CF battery delivers a Coulombic efficiency of 99 % over 2000 cycles with a current density of 1 A g-1. This study would lead to opening of a new paradigm for the development of highly reversible aqueous rechargeable ZIBs.

Effect of pyrolysis temperature and hydrothermal activation on structure, physicochemical, thermal and dye adsorption characteristics of the biocarbons.

In this study, the possibility of using sawdust from mixed woods to obtain biocarbons in the pyrolysis and steam activation using microwave radiation as an energy source was investigated. Biocarbons were characterized based on the results of N2 adsorption, thermogravimetric analysis (TGA), Fourier spectroscopy (ATR-FTIR), and Raman spectroscopy. Surface characterization was performed by Boehm titration and pHpzc determination. The adsorption capacity of methylene blue (MB) and methyl orange (MO) was studied. It was proved that the pyrolysis temperature and hydrothermal activation increased the biocarbons structural, surface and adsorption parameters of the obtained biocarbons. The amorphous materials of small specific surface area with a significant share of micropores were obtained. The steam activation resulted in significant development of the porous structure (to SBET =729.2 m2 /g and Vp =0.36 cm3 /g). The presence of functional groups, mainly phenolic ones, and pHpzc values indicating a potential for adsorption applications regarding MO and MB were found. The highest sorption capacity concerning MB (qe =122.8 mg/g) and MO (qe =99.1 mg/g) was observed for the steam-activated biocarbon BC-800MW . Using microwave energy hydrothermal activation proved very efficient, resulting in significant surface area and porosity development with a small loss of carbon matter.

Efficient Decontamination: Caffeine/Triclosan Removal using Rice Husk in Batch and Fixed-Bed Columns

Abundant, easily accessible, and low-cost agro-industrial residues represent attractive alternatives for removing emerging contaminants from water. In this work, the aqueous adsorption of caffeine/triclosan onto rice husk (RH) was studied in batch and continuous processes. For this purpose, adsorbents with three particle size ranges (120–150, 300–600, 800–2000 µm) were prepared and evaluated. The composition, structure, surface morphology, functionality, and specific surface area of the RH biosorbents were determined. This characterization revealed that RH primarily consists of lignin, cellulose, and hemicellulose, making up to 80.1% of its composition. RH also exhibited an irregular surface, with several functional groups (OH, C=O, CH, C=C, C-OH), and a relatively small specific surface area (1.18 m2/g). Batch tests were carried out using different RH sizes, doses (1–50 g/L), and contact times (5–300 min), using 20 mL of caffeine/triclosan solutions (30 mg/L). Tests were conducted to fit the most adequate kinetics and isotherm models. The optimal doses (g/L) for caffeine and triclosan removal were 4.5 and 1.5 with small RH, 8.5 and 2.5 with medium RH, and 50.0 and 10.0 with large RH, respectively. The optimal contact times for all three particle sizes were 180 and 60 min. Triclosan removal was greater than that of caffeine (2.5–25.5%) with all three particle sizes, requiring less adsorbent (2.5–5.0 times) and shorter times (3 times). The experimental data fit better the Sips isotherm and Elovich kinetics models. The small (120–150 µm) particles achieved the highest caffeine/triclosan batch adsorption capacities (6.3/28.6 mg/g). Continuous tests were performed on fixed-bed columns of 1 cm in diameter, packed with 4, 5, and 8 cm of RH, operated with hydraulic loading rates between 2 and 4 m3/m2day. Small particles also reached the highest adsorption capacity in the removal of caffeine (352.7 mg/L) and triclosan (3797.2 mg/L), and the experimental data were well-fitted to the Bohart–Adams model. The research results not only demonstrate the effective removal of contaminants but also illustrate the versatility and applicability of rice husk in various conditions and systems.

A facile reflux method to produce ternary CQDs/P25/NH2−MIL-125 for photocatalytic degradation of methylene blue under simulated solar light

BackgroundTo enhance the photocatalytic performance of commercial titanium dioxide (P25), carbon quantum dots (CQDs) and NH2−MIL-125 were utilized to address its limitations arising from the large bandgap and small specific surface area. The CQDs were employed to broaden the range of solar light absorption, while NH2−MIL-125 was used to disperse P25 with a higher specific surface area. MethodsA facile reflux method was conducted to synthesize CQD/P25/NH2−MIL-125 composite materials. The up-conversion photoluminescence (UCPL) effect of CODs was leveraged to convert longer wavelengths of light into shorter ones, facilitating P25 and NH2−MIL-125 to enhance photocatalytic performance. Significant findingsThe UCPL effect of CQDs not only broadened the light absorption range but also retarded the recombination of photo-induced electron-hole pairs, leading to improved photocatalytic reactions. Furthermore, the effect of additional amounts of CQDs was investigated, and it was found that 1wt% CQDs/P25/NH2−MIL-125 followed first-order kinetics, with the highest rate constant (k1) of 0.0141.

Synthesis of small size lead-free Cs3Bi2xSb2−2xBr9 solid-solutions using a spatially confined growth method for efficient photocatalytic CO2 reduction

The small size lead-free Cs3Bi0.6Sb1.4Br9 solid-solution spatially confined in MCM-41 molecular sieve shows an outstanding performance for photocatalytic CO2 reduction to CO.

Analysis of physicochemical and tribological properties of nano alumina-based gear oil developed from effluent of lube oil blending plant

Industrial wastewater, also known as effluent has been identified as one of the leading sources of environmental pollutions worldwide. The establishment of lube oil blending plants in Nigeria has led to a continuous discharge of industrial effluent in densely populated areas. This threatens the well-being of humanity, plants, aquatic lives and construction soils. This research paper focused on developing a nano alumina-based effluent gear oil from effluent of lube oil blending plants as an alternative means of mitigating its threats on the environment. Nano lubricant are used in gearboxes for better thermal, friction and anti-wear properties. This is due to the small size and high specific surface area to volume ratio of the nanoparticles. Furthermore, due to their excellent mechanical and thermal properties, easy dispersal in most fluids, inexpensiveness, ease of manufacture, and aspect ratio, the Al2O3 nanoparticles are recently being used by researchers as an additive in gear oils to improve tribological properties, increase power efficiency, extend equipment lifetimes, and lower operating cost. In this work, the alumina nanoparticle was synthesized using co-precipitation method, after which it was characterized using Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) analysers. After the development of Al2O3-based gear oil from the effluent, the physicochemical and tribological properties of the alumina-based effluent gear oil samples were investigated with varied weight percentages of Al2O3 nanoparticles. The Differential Scanning Calorimetry (DSC) and Computational Fluid Dynamics (CFD) thermal analyses of nano alumina-based gear sample was investigated after obtaining the suitable sample among the sample blends developed. The dispersion of the nanoparticle in the effluent oil improved the specific gravity and pour point whereas a slight reduction was observed in kinematic viscosity at 100 °C, viscosity index and flash point. However, viscosity index and flash point values are conforming to the minimum requirements of API EP 85W90 and ISO 100 standard values. The anti-wear property was observed to significantly improved by 26.14%, at 0.4 wt% nanoparticles concentration. The results showed that, the pure effluent oil recovered is more thermally stable than the 0.4 wt% nano alumina-based effluent gear oil sample, whereas the nano gear oil sample has a higher thermo-oxidative stability than the pure effluent oil. Finally, temperature profiles from the simulation results also ensured a better performance of the 0.4 wt% alumina-based effluent gear oil developed, at 1500 rpm speed of rotation by 6.7% and 8.9% and at 4000 rpm is by 5.9% and 7.8% than the API EP 85W90 and pure effluent oil samples respectively. Hence, based on the results obtained, the study indicated that the effluent oil from lube oil blending plants can be used as gear oil with the dispersion of alumina nanoparticles.

Effect of interface layer on the enhancement of thermal conductivity of SiC-Water nanofluids: Molecular dynamics simulation

To investigate the impact of interfacial layer effects on the thermal conductivity of nanofluids and the microscopic mechanisms of enhanced thermal conductivity, this study employed non-equilibrium molecular dynamics to compute the thermal conductivity, number density, radial distribution function, and mean square displacement distribution of SiC nanofluids. The impact of nanoparticle volume fraction and particle size parameters on the thermal conductivity of nanofluids and the structure of interfacial adsorption layers was discussed. The simulation calculation results show that the coefficient of thermal conductivity of nanofluid is positively related to the volume fraction of nanoparticles, increasing from 0.6529 W/(m·K) to 0.8159 W/(m·K), and the enhancement of thermal conductivity by the volume fraction can be up to 33.97 %. The thermal conductivity is inversely correlated with the change in particle size, and the maximum improvement in thermal conductivity by particle size can reach up to 12.05 %. The simulated results of the thermal conductivity of nanofluid are almost consistent with the predicted results of the Yu&Choi model, and the error is controlled within 5 %. Simultaneously, the thickness of the interfacial adsorption layer decreases with an increase in particle size. This reduction arises due to larger particles having a smaller specific surface area, resulting in fewer particle surfaces covered by the interface layer. Moreover, the impact of particle size on the arrangement and affinity of molecules within the interface layer contributes to this decrease. Overall, interface layer effects exhibit a dual impact on the thermal conduction of nanofluids. The structured formation and high-density distribution of the adsorption layer contribute to enhanced heat transfer, while thermal resistance between nanoparticle surfaces and the fluid restricts heat transmission.

Supramolecular Self-Assembly of g-C3N4 Nanoplatform as Drug Delivery Carriers for Cancer Therapy

Graphite carbon nitride (g-C3N[Formula: see text] polymer with two-dimensional planar structure is a new star in nanodrug delivery systems in recent years because it shows characteristics of low cost, nontoxicity, biocompatibility and easy functionalization. However, conventional g-C3N4 shows bulk, macro size, small specific surface area and poor water solubility. To improve this, most works are always confined to physical ultrasound, oxidative peeling or template-strategy, which have the disadvantages of redundant steps, environment-unfriendliness and high cost. In this paper, a modified supramolecular self-assembled strategy was carried out to construct a novel graphitic carbon nitride nanoplatform (named by CA-MA[Formula: see text] using melamine and cyanuric as precursors. The chemical structure characterization, drug loading experiment and cell tests in vitro of the CA-MA[Formula: see text] nanoplatform were carried out and discussed in detail. Results indicated that the obtained samples show enhanced specific surface area, more exposed groups and good biocompatibility. Compared to the traditional carbon nitride (named by MA-CN), the newly prepared CA-MA[Formula: see text] carrier shows improved drug loading efficiency and good pH-responsive loading, as well as releasing. Cell uptake experiment demonstrates that CA-MA2-DOX can be swallowed by cancer cells and during treatment of the cancer cell process, the CA-MA2-DOX complex experiences phagocytizing by the cancer cell, controlled-release DOX and kills the cancer cell after DOX was passively diffused into the nucleus. CA-MA2-DOX exhibited significant in vitro antitumor activity. To our knowledge, this is the first time the supramolecular self-assembled method was used in carbon nitride nanocarrier construction for cancer treatment.

Heterogeneous La and CeOx co-promoted SAPO-11 catalyst for catalytic upgrading of cellulose-derived volatile and methanol into hydrocarbon-rich fuels

In this paper, a series of La–Ce co-doped SAPO-11 catalysts with various La to Ce ratio were developed via wet impregnation method then employed in catalytic cellulose and methanol co-pyrolysis to produce hydrocarbon-rich biofuels. Comprehensive characterization technologies including X-ray diffraction, X-ray photoelectron spectroscopy, N2 physisorption, scanning electron microscope, transmission electron microscope, ammonia temperature-programmed desorption, Pyridine-infrared, and thermal gravimetric analyzer, were conducted to unveil the physicochemical properties, structure properties and acidity of as-prepared catalysts. Additionally the product content; aromatic selectivity and synergetic effect were also investigated. Additionally possible conversion pathway, deactivation mechanism and reusability were also deduced. La and Ce showed a certain synergetic effect and exhibited superior catalytic deoxygenation activity due to La–O and Ce-Ox species, suitable Brønsted acidity, abundant oxygen vacancies and enhanced mesopores structure, which was facilitated to promote the selectivity of hydrocarbon. Higher La content was fascinated to generate furans and ketones compounds, due to lower Brønsted acid site and smaller specific surface area. In contrast, higher CeOx content was beneficial to hydrocarbon formation via Diels-Alder reaction and dehydro-aromatization due to higher Brønsted acid site, total acidity, higher specific surface area, mesoporous pore volume as well as strong oxygen affinity of CeOx. The maximum proportion hydrocarbon, aromatics and minimum contents coke was obtained over 1La–1Ce/SAPO-11 were 77.96 %, 55.82 % and 9.81 %, respectively. Additionally, 1La–1Ce/SAPO-11 catalyst exhibited outstanding reusability and stability after four cycles; nearly ∼96 % relative content of hydrocarbon was maintained after regeneration test. Hence, the insight into the synergetic catalysis between La and CeOx species could provide a new potential possible pathway for design and synthesized efficient and eco-friendly bimetallic catalyst for selective catalytic deoxygenation organic solid waste biomass for valuable chemicals.

Development of sulfhydryl grafted hierarchical porous geopolymer for highly effective removal of Pb (II) from water

Geopolymers have captured increasing attention in the adsorption of lead ions due to their zeolite-like three-dimensional network structure, and several advantages such as low cost and environmental friendliness. However, their adsorption performance is limited by a small specific surface area and fewer adsorption sites. In this study, a metakaolin-based geopolymer was first pretreated with different concentrations of nitric acid to increase the porosity and surface area. Subsequently, the sulfhydryl functional group was grafted onto the above hierarchical porous geopolymer, which is a inorganic material with multistage pore structure. The result of N2 adsorption and desorption results demonstrated that an increase in specific surface area and number of grafting sites for sulfhydryl groups with increasing acid concentration when the highest nitric acid concentration used is 5 mol/L and acid treatment time is for 5 h. The specific surface area of the fabricated geopolymers was as high as 343.87 m2/g and the concentration of silanol groups reached 4.46 mmol/g at 3 mol/L acid concentration. The maximum Pb2+ adsorption quantities for SH-1HGeo, SH-2HGeo, and SH-3HGeo samples were 173.2 mg/g, 239.8 mg/g, and 386.3 mg/g, respectively. The adsorption processes were in accordance with the pseudo-second-order kinetic model and the Langmuir models, indicating that the Pb2+ adsorption on the sulfhydryl grafted hierarchical porous geopolymer was mainly chemisorption and monolayer adsorption. The contribution of different Pb2+ adsorption mechanism on geopolymer was ion-exchange, while that on SH-3HGeo was functional group complexation.