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In this work, a solvent-free ZnO-template method is used to synthesize hierarchical porous carbons (denoted as HPC

In this work, a novel Ni–Cu/Al2O3 catalyst is used to trigger the partial oxidation of methanol (POM) for hydrogen production. This reaction system also employed ultrasonic sprays to aid in dispersing methanol fuel. The prepared catalyst is analyzed by scanning electron microscope (SEM), energy-dispersive X-ray (EDX) spectroscopy, and X-ray diffraction (XRD) to explore the catalyst's surface structure, elemental composition, and physical structure, respectively. The Box-Behnken design (BBD) of response surface methodology (RSM) is utilized for experimental design to achieve process optimization. The operating parameters comprise the O2/C molar ratio (0.5–0.7), preheating temperature (150–250 °C), and weight percent (wt%) of Ni (10–30%) in the catalyst. The results show that methanol conversion is 100% in all the operating conditions, while the reaction temperature for H2 production ranges from 160 to 750 °C, stemming from heat released by POM. The significance and suitability of operating conditions are also analyzed by analysis of variance (ANOVA). It indicates that the highest H2 yield is 2 mol (mol CH3OH)−1, occurring at O2/C = 0.5, preheating temperature = 150 °C, and Ni wt% = 10. Compared with the commercial h-BN-Pt/Al2O3 catalyst, the prepared Ni–Cu/Al2O3 catalysts have higher activity for H2 production. The O2/C ratio is the most influential factor in the H2 yield. Moreover, the interaction of the O2/C ratio and Ni content is sound, reflecting that changing Ni content in the catalyst will affect the trend of H2 yield under each O2/C.

Mesoporous Cu-Ni/Al2O4 catalyst of high surface area (176 m2g−1) is synthesized through a simple hydrothermal reconstruction process by using low-cost activated alumina as the aluminate source without organic templates. The desired mesoporous structure of the catalyst is formed by the addition of Cu2+ and Ni2+ metal ions in the gel solution of the activated alumina followed by hydrothermal treatment at 70 °C and calcination at temperatures in the range of 600 to 800 °C. To consider the environmental concern, we found the concentration of the Cu2+ and Ni2+ ion in the residual filtrate is less than 0.1 ppm which satisfies the effluent standard in Taiwan (2O4 composites are investigated as well. In addition, the Cu-Ni/Al2O4 catalyst synthesized at pH 9.0 with a hydrothermal treatment time of 24 h and a calcination temperature of 600 °C is used for hydrogen production via the partial oxidation of methanol. The conversion efficiency is found to be >99% at a reaction temperature of around 315 °C, while the H2 yield is 1.99 mol H2/mol MeOH. The catalyst retains its original structure and surface area following the reaction process, and is thus inferred to have a good stability. Overall, the hydrothermal reconstruction route described herein is facile and easily extendable to the preparation of other mesoporous metal-alumina materials for catalyst applications.

X-ray photoelectron spectroscopy, reflection–absorption infrared spectroscopy, temperature-programmed reaction/desorption, and density functional theory calculations have been performed to investig...

An investigation is performed into the efficiency of the Streptomyces griseus HUT 6037 enzyme immobilized in three different mesoporous silicas, namely mesoporous silica film, mesocellular foam, and rod-like SBA-15. It is shown that for all three supports, the pH value changes the surface charge and charge density and hence determines the maximum loading capacity of the enzyme. The products of the enzyme hydrolytic reaction are analyzed by 1H-NMR. The results show that among the three silica supports, the mesoporous silica film (with a channel length in the range of 60–100 nm) maximizes the accessibility of the immobilized enzyme. The loading capacity of the enzyme is up to 95% at pH 7 and the activity of the immobilized enzyme is maintained for more than 15 days when using a silica film support. The order of the activity of the enzyme immobilized in different mesoporous silica supports is: mesoporous silica film > mesocellular foam > rod-like SBA-15. Furthermore, the immobilized enzyme can be easily separated from the reaction solution via simple filtration or centrifugation methods and re-used for hydrolytic reaction as required.

In this study, a novel renewable double-energy system, coupling activated biochar production and thermoelectric generation, is conducted and demonstrated. In the installed 13 thermoelectric modules...

The separation of oily wastewater, specifically emulsions, is a crucial global issue. Possible strategies for the efficient separation of emulsified oil/water mixtures through sustainable and environmentally friendly materials have recently drawn considerable attention. In our study, we prepared superwetting water caltrop shell biochar (WCSB) via a top-lit-updraft carbonization procedure. The as-prepared WCSB was characterized by superhydrophilicity, underwater superoleophobicity, underoil superhydrophilicity, and underoil water adsorption ability. Because of its superwetting properties, WCSB was used for the separation of both surfactant-stabilized oil-in-water emulsions (SOIWEs) and surfactant-stabilized water-in-oil emulsions (SWIOEs) with very high fluxes (up to 74,700 and 241,000 L m

Biochars were derived from wood and water caltrop shell waste for the adsorption of Cr(III) and Cu(II) in solutions. In the competitive adsorption, Cu(II) had a good affinity for the water caltrop shell and blended biochars. The blended biochar was a mixture of wood and water caltrop shell biochars. Each biochar adsorption equilibrium data fit well with the Freundlich model. The effectiveness of the adsorption of Cr(III) and Cu(II) solutions utilizing biochar is proven to be effective in continuous adsorption columns, and the adsorption performance is verified with model simulation.

Hollow Li2FeSiO4 spheres have been successfully prepared using hollow silica spheres as both reactant and template, for which the thickness of the nanoscale Li2FeSiO4 thin shells are about 50 nm. Then, the hollow Li2FeSiO4 spheres were coated by phenolic resin as a carbon precursor to obtain the hollow Li2FeSiO4/Carbon sphere (HLFS/C) composite. The structure characterizations by X-ray diffraction, transmission electron microscopy and scanning electron microscopy show that the HLFS/Cs are hollow structures with high purity. When used as the cathode material under charge/discharge rates at 0.05C (1C = 166 mAh g−1), the HLFS/C exhibited a capacity of 155 mAh g−1 with good cycle stability. Furthermore, the HLFS exhibited capacities of 820, 650 and 420 mAh g−1 for 0.15C, 0.3C and 0.6C rates for anode application, respectively, with good cycle stability. The hollow structure of HLFS/C enables us to overcome the aggregation and structural instability problems, which is essential for the improvement of the electrochemical performance.

In this study, mesoporous Cu Fe/silicate catalysts were obtained from a simultaneously mixing the NaOH and metal-ion solution to sodium silicate solution and a hydrothermal treatment under alkaline condition without using any organic template. During hydrothermally reaction, the amorphous metal-silicate would reconstruct and formation of the mesostructured Cu Fe/silicate. At appropriate pH values, the silicate species can strongly bind with the Cu2+ ions to form the stable Cu Fe/silicate, and the [Cu2+] in the final filtrated solution is lower than the effluent standard in Taiwan (1.0 ppm). To find the appropriate synthetic parameters, the effects of the pH value, metal to silicate ratio, and the hydrothermal treatment time on the surface areas and mesostructure of the resulted Cu Fe/silicates were discussed in detail. In practice, the mesoporous Cu Fe/silicate catalyst with high surface area of 547 m2g-1 demonstrated a high methanol conversion within 1 h up to >99% at 180 °C to be used as high-performance catalysts for steam reformer of methanol.

Mesoporous Mn3O4-Al2O3 catalyst with highly dispersed Mn3O4 and a high surface area is prepared using a one-pot synthesis technique without any templates. The synthesis procedure is environmentally friendly due to the low concentration of residual metal ions in the filtered solution, which allows for its direct release without further processing. The results show that the presence of Mn2+ ions stabilizes the Al(OH)3 crystal phase during hydrothermal treatment and prevents the formation of the AlOOH phase otherwise observed in the absence of Mn2+ ions. Because of the high stability of the resulted Mn3O4-Al(OH)3 nanoplatelets, a mesoporous Mn3O4-Al2O3 structure was formed via the dehydration of the Al(OH)3 after high-temperature calcination. The catalytic efficiencies of the Mn3O4-Al2O3 catalysts in the low-temperature selective catalytic reduction of NO with NH3 are examined under various reaction temperatures in the range of 80–200 °C. The results show that the NO conversion reaches as much as 94% at a reaction temperature of 80 °C. The proposed synthesis method thus holds considerable promise for the green, low-cost and scalable production of highly mesoporous Al2O3-based catalysts.

Cu-Mn and Cu-Mn-Ce oxide-incorporated mesoporous silica was formed by hydrothermally exfoliating silicate, and the physicochemical properties and NO/Hg0 removal efficiency were investigated. The exfoliation induced structural reformation, resulting in a large specific surface area and the uniform dispersion of metal oxides on the surface. The transfer of valences between Cu2+ and Mn3+ in the Cu-Mn silica contributed to the single reduction peak displayed in the H2 temperature-programmed reduction profiles and the high Mn4+/Mn and Cu+/Cu ratios observed via X-ray photoelectron spectroscopy (XPS). The high oxygen lability of the Cu-Mn silica may have inhibited its ability to remove NO. By contrast, when SO2 was present, incorporating Ce enhanced the NO removal efficiency due to the increased number of Bronsted acid sites. Hg0 removal tests indicated that adsorption was the primary removal mechanism for both the Cu-Mn and the Cu-Mn-Ce silica samples. Cu2Mn8 exhibited the highest Hg removal efficiency, suggesting that Ce’s enhancing effect on Hg0 adsorption was diminished when a large amount of Mn was present. Of the gaseous components, the adsorbed HCl was mainly responsible for the oxidation and subsequent adsorption of Hg0. Furthermore, with the addition of SO2, the competitive adsorption of SO2 and the resulting HgCl2 did not decrease the Cu-Mn silica’s efficiency in oxidizing Hg0, but the oxidized Hg was less adsorptive.

Resource-recovered CuOx-CeOx/SiO2 samples were prepared by using rice-husk-derived silica modified with recycled copper ion from panel industry wastewater for controlling Hg0 and NO emissions from simulated flue gases. By using the silicate exfoliation method for sample preparation, the presence of Cu and Ce oxides could increase the specific surface area (SBET) of SiO2. 50%Cu-10%Ce/SiO2 having the largest SBET showed significant NO removal. XRD results indicated that significant CuO diffraction peaks were not detected among all the CuOx/SiO2 samples, suggesting that CuOx was highly dispersed on the surface. SEM and TEM images showed that the uniform spherical SiO2 particles have changed into plate-like structure, further confirming the occurrence of structural rearrangement after incorporated with Cu/Ce oxides via silicate exfoliation. XPS results showed that Cu2+ and Ce4+ were the major valence states presenting in the samples. H2-TPR and NH3-TPD indicated that the 50%Cu/SiO2 and 50%Cu-10%Ce/SiO2 had greater redox ability and stronger acidity as compared to those containing smaller amounts of CuOx and CeOx. Cu and Ce modification was shown to successfully improve the NO removal efficiency. 50%Cu-10%Ce/SiO2 had the best NO conversion efficiency of 70–85% with a broad temperature window of 150–300°C. 50%Cu/SiO2 exhibited the greatest total Hg removal efficiency of 88.2% among all the tested samples at 150°C and remained almost the same removal efficiency at 250°C. These results suggest that the recycled Cu modified rice-husk-derived SiO2 is feasible for not only controlling Hg0 and NO emissions but also recovery of agricultural and industrial wastes.

A green synthesis method is proposed for the preparation of nitrogen-doped multiporous carbons (denoted as N-MPCs) from water-caltrop shell (WCS) using eggshell waste as both a nitrogen-dopant and an activating agent. It is shown that the surface area, porosity, yield and nitrogen content of the as-prepared N-MPCs can be easily controlled by adjusting the activation temperature. Moreover, in oxygen reduction reaction (ORR) tests performed in O2-saturated 0.1 M KOH(aq) electrolyte containing 1.0 M methanol, the N-MPC catalysts show a high ORR stability and good resistance to methanol corrosion. In addition, as a cathode material in Al–air battery tests, the N-MPCs achieve a power density of 16 mW g−1 in a saturated NaCl(aq) electrolyte. Overall, the results show that the N-MPCs have a promising potential as a green and sustainable material for ORR catalysis applications.

A novel moderately halophilic bacterial strain, designated YIM 93176T, was isolated from a saltern in Korea and subjected to a polyphasic taxonomic study. This isolate YIM 93176T was observed to grow in the presence of 0–22% (w/v) NaCl and at pH 6.0–10.0 and 10–45 °C; optimum growth was observed with 5–10% (w/v) NaCl and at pH 7.0–9.0 and 28–37 °C. Based on 16S rRNA gene sequences analysis, the nearest relatives were Lentibacillus alimentarius M2024T (96.5% similarity), followed by Virgibacillus carmonensis LMG 20964T (96.0%) and the other type strains of the family Bacillaceae, but phylogenetic analysis indicated that strain YIM 93176T belonged to the cluster comprising type species of the genus Lentibacillus. Genome sequencing of strain YIM 93176T revealed a genome size of 3.2 Mb and a DNA G + C content of 40.5 mol%. The major fatty acids were anteiso-C15:0 (40.7%) and iso-C15:0 (26.4%), while the predominant respiratory quinone was menaquinone 7. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. These genotypic and chemotaxonomic characteristics supported affiliation of strain YIM 93176T to the genus Lentibacillus. In addition, phenotypic characteristics could distinguish strain YIM 93176T from its closely related species in genus Lentibacillus. Based on the cumulative evidences from the polyphasic taxonomic study, strain YIM 93176T represents a novel species of the genus Lentibacillus, for which name Lentibacillus saliphilus sp. nov. (type strain YIM 93176T = CCTCC AB 208139T = DSM 21375T) is proposed.

Background/Purpose One effective way to deal with dentin hypersensitivity is to develop materials to seal the tubules. The porous bio-calcium carbonate-silica (BCCS) contained well-dispersed CaCO3 would form calcium phosphates to seal the dentinal tubules when mixed with an acidic solution. The acidic hydrothermal treatment and calcination to isolate the BCCS from the agricultural waste like equisetum grass was used, which would be more environmentally friendly than chemically synthesized mesoporous biomaterials. The aim of this study was to develop mesoporous materials from natural resources to occlude the dentinal tubules which could be more environmentally-friendly. Methods Dentin disc samples were prepared and treated with different methods as follows: (1) BCCS mixed with H3PO4; (2) BCCS mixed with KH2PO4; (3) Seal & Protect® was used as a comparison group. Sealing efficacy was evaluated by measuring the depths and percentages of precipitate occlusion in dentinal tubules with SEM. Results The N2 adsorption–desorption isotherm of the BCCS demonstrated a pore size of around 15.0 nm and a surface area of 61 m2g-1. From the results of occlusion percentage and depth, the BCCS treated with H3PO4 or KH2PO4 demonstrated promising sealing efficacy than the commercial product. Conclusion This synthetic process used the agricultural waste equisetum grass to produce bio-calcium carbonate-silica would be environmentally friendly, which has great potential in treating exposed dentin related diseases.

Bor-Shiunn Lee,1,2 Hong-Ping Lin,3 Jerry Chun-Chung Chan,4 Wei-Chuan Wang,2 Ping-Hsuan Hung,2 Yu-Hsin Tsai,4 Yuan-Ling Lee1,2 1Graduate Institute of Oral Biology, 2Graduate Institute of Clinical Dentistry, School of Dentistry, National Taiwan University and Hospital, Taipei, 3Department of Chemistry, National Cheng Kung University, Tainan, 4Department of Chemistry, National Taiwan University, Taipei, Taiwan, Republic of China Abstract: Mineral trioxide aggregate (MTA) is the most frequently used repair material in endodontics, but the long setting time and reduced mechanical strength in acidic environments are major shortcomings. In this study, a novel sol-gel-derived calcium silicate cement (sCSC) was developed using an initial Ca/Si molar ratio of 3, with the most effective mixing orders of reactants and optimal HNO3 catalyst volumes. A Fourier transform infrared spectrometer, scanning electron microscope with energy-dispersive X-ray spectroscopy, and X-ray powder diffractometer were used for material characterization. The setting time, compressive strength, and microhardness of sCSC after hydration in neutral and pH 5 environments were compared with that of MTA. Results showed that sCSC demonstrated porous microstructures with a setting time of ~30 min, and the major components of sCSC were tricalcium silicate, dicalcium silicate, and calcium oxide. The optimal formula of sCSC was sn200, which exhibited significantly higher compressive strength and microhardness than MTA, irrespective of neutral or pH 5 environments. In addition, both sn200 and MTA demonstrated good biocompatibility because cell viability was similar to that of the control. These findings suggest that sn200 merits further clinical study for potential application in endodontic repair of perforations. Keywords: acidic environment, compressive strength, mesoporous, mineral trioxide aggregate, mixing order, sol-gel reaction

A lithium ion battery (LIB) anode is prepared consisting of silicon and a reduced graphene oxide (Si/r-GO) composite deposited on a three-dimensional (3D) carbon fiber (CF) current collector. The morphology, structure and textural properties of the as-prepared Si, Si/r-GO composite and Si/r-GO/CF electrode are characterized using scanning electron microscopy, X-ray diffraction and N2 adsorption–desorption isotherms, respectively. The reversible capacity of the Si/r-GO/CF electrode (>1000 mA h g−1 at the rate of 0.1C) is found to be significantly higher than that of a Si/r-GO electrode with a traditional 2D copper foil collector. Moreover, the Si/r-GO/CF electrode exhibits an excellent rate performance of 280 mA h g−1 even at a rate of 10C due to the effective conductivity improvement and a capacitor-like behavior offered by the CF networks. In addition, the Si/r-GO/CF coin cell shows a low resistance of 20 Ω in charge transfer. Finally, the CF skeleton serves as a solid scaffold, which inhibits the aggregation of the Si/r-GO composite during usage, and therefore leads to a long cycle life (i.e., a capacity retention of more than 95% after 100 cycles).

Implementation of photosynthetic microorganism, like Thermosynechococcus sp. CL-1 (TCL-1), is considered as an eco-friendly strategy for carbon dioxide fixation and nutrient utilization in wastewater. However, high level of ammoniacal nitrogen carries out toxicity to TCL-1 cell and adsorption can be applied as a pre-treatment stage. This study observed application of iron-silicate on ammoniacal nitrogen adsorption in non-sterilized and undiluted swine wastewater as pre-treatment for TCL-1 cultivation for CO2 fixation, NH4+-N degradation, and phycobiliprotein generation. The utilization of 100 g/L iron-silicate performed efficient adsorption with the quantity of 4.05 mg-N/g-Fe/Si and fitted the pseudo-first-order adsorption with R2 value of 0.993. The adsorption pre-treated swine wastewater was implemented as TCL-1 growth medium under the 1000 μE/m2/s light intensity for 12 h. The TCL-1 biomass growth, CO2 fixation, and NH4+-N removal rate during cultivation period reached to 31.67 ± 1.25; 57.54 ± 6.09; and 6.05 ± 0.20 mg/L/h respectively. Phycobiliprotein as a byproduct was generated with the productivity of 13.9 mg/g/h. Thus, coupling iron-silicate for pre-treatment step of TCL-1 cultivation in swine wastewater is eco-friendly strategy to reduce water demand for dilution, ignite phycobiliprotein accumulation during the CO2 fixation and nutrient utilization process.

MnOx- and MnOx-CeOx-impregnated SiO2 particles were developed from waste rice husk via a hydrothermal synthesis for removal of Hg0 and NOx. MnOx of 5 or 20 wt% associated with 5 or 10 wt% CeOx was impregnated into resource-recovery mesoporous SiO2. The presence of MnOx and CeOx reduced the specific surface area (SBET) and pore volume of the SiO2 particles. Nevertheless, MnOx(5%)-CeOx(5%)/SiO2 possessed the largest SBET (123 m2 g−1) among the impregnated samples. Electron microscopy images show that the metal-oxide-impregnated SiO2 was plate-shaped with sizes of 3–10 μm. Mn4+/Mn3+ and Ce4+/Ce3+ were the major valence states in the MnOx-CeOx/SiO2 samples; the ratio of Mn4+/Mn3+ increased as CeOx was present. The presence of both amorphous/highly dispersed and crystalline MnOx was confirmed by X-ray diffraction and X-ray photoelectron spectroscopy. Removal of Hg0 and NO was achieved by both MnOx/SiO2 and MnOx-CeOx/SiO2 at between 150 and 350 °C. MnOx-CeOx/SiO2 showed greater Hg and low-temperature NO removal potentials than MnOx/SiO2, with MnOx(20%)-CeOx(10%)/SiO2 having Hg0 removal efficiency of 96% at 150 °C and nearly 100% reduction of NO under a broad operation window of 100–300 °C. These results indicate that resource recovery of waste rice husk for producing SiO2 adsorbent/catalyst for Hg0 and NOx removal is successful.

The present study focused on the preparation and characterization of a bio-based carbon-silica material derived from rice husk agricultural waste and its function in epoxy matrix for electronic packaging applications. X-ray diffraction (XRD) analysis, N2 adsorption/desorption isotherms, and scanning electron microscopy were used to characterize the structure as well as morphology of the resultant carbon–silica material, namely black rice husk ash, called BRH. Thermogravimetric analysis results suggest that improved thermal stability can be achieved by reducing the ionic content of the BRH materials through the pre-acid-hydrothermal technique. The ionic content of [Cl−], [Na+], and [K+] of the BRH sample respectively were 4.3, 9.8, and 9.0 ppm after further post-hydrothermal process. In addition, the XRD diagram shows that the structure of the calcined BRH material, is in amorphous form, which is non-toxic to humans. For packaging application, an improvement of 147% in storage modulus and 49% in CTE by the addition of 46% filler was realized. In addition, compared with pure polymer, the thermal conductivity values of the epoxy/pre-BRH composites were improved by 142%. From these results, it was concluded that this BRH filler derived from waste rice husks can promote the thermal stability, thermal-mechanical strength, and thermal conduction of the Epoxy/BRH composites.

Temperature-programmed reaction/desorption (TPR/D) and reflection–absorption infrared spectroscopy (RAIRS) have been employed to study the reactions of CH2═CHBr and CH3CHBr2 on Cu(100) and O/Cu(100). In the TPR/D study, CH2═CH—CH═CH2 is the sole product detected from the reaction of CH2═CHBr adsorbed on Cu(100) and featured by complex, coverage-dependent thermal desorption profiles (∼220–380 K). The preadsorbed oxygen can modify the evolution behavior of 1,3-butadiene from the CH2═CHBr reaction but has no influence on the main 1,3-butadiene formation at 265 K. Moreover, the surface oxygen participates in the CH2═CHBr reaction, forming an intermediate of >C═C═O, as well as additional products of H2O, C2H2, CO, and CO2, presumably via H-abstraction. New reaction pathways, which are otherwise not observed in the TPR/D study, are opened when CH2═CHBr impinges on Cu(100) at high temperatures. At 500 K, H2, C2H2, and C2H4 are generated from the incident CH2═CHBr molecules upon Cu(100). The reaction of adsorbed ...