Phenylsulfonic Acid Groups Research Articles

Strategy Toward Semiconducting Ti3C2Tx‐MXene: Phenylsulfonic Acid Groups Modified Ti3C2Tx as Photosensitive Material for Flexible Visual Sensory‐Neuromorphic System

AbstractThe excellent electronic and electrochemical properties make 2D MXenes suitable candidates for sensors, batteries, and supercapacitors. However, the metallic‐like behavior of MXenes hinders their potential for optoelectronic devices such as photodetectors. In this study, the band gap of metalloid Ti3C2Tx MXene is successfully opened to 1.53 eV with phenylsulfonic acid groups and realized a transistor and high‐performance near‐infrared photodetector array for a flexible vision sensory‐neuromorphic system. The phenylsulfonic acid groups modified Ti3C2Tx MXene (S‐Ti3C2Tx)‐based flexible photodetector has a maximum responsivity of 8.50×102 A W−1 and a detectivity of 3.69×1011 Jones under 1064 nm laser irradiation. Moreover, the fabricated flexible vision sensory‐neuromorphic system for image recognition realizes a high recognition rate >0.99, leading to great potential in the field of biological visual simulation and biomimetic eye. Besides conventional devices with Au as the conductive electrodes, all Ti3C2Tx MXene‐based devices are also fabricated with S‐Ti3C2Tx as the photosensitive material and unmodified Ti3C2Tx as the conductive electrodes, exhibiting comparable optoelectronic performances.

Enhanced Ageing Performance of Sulfonic Acid-Grafted Pt/C Catalysts.

Chemical functionalization of carbon support for Pt catalysts is a promising way to enhance the performance of catalysts. In this study, Pt/C catalysts grafted with various amounts of phenylsulfonic acid groups were prepared under mild conditions. The influence of sulfonic acid groups on the physiochemical characteristics and electrochemical activities of the modified catalysts were studied using X-ray diffraction, X-ray photoelectron spectroscopy, a transmission electron microscope, and cyclic voltammetry (CV). The presence of the chemical groups enhanced the hydrogen adsorption onto/desorption off the Pt surface during the CV cycling. In contrast, the hydrogen peaks of the grafted catalysts increased after 500 CV cycles, especially for Pt (111) facets. The highest electrochemical surface area (ECSA) after the aging test was obtained for the catalyst with 18.0 wt.% graft, which was ca. 87.3% higher than that of the non-functionalized Pt catalyst. In the density functional theory (DFT) calculation, it was proven that SO3H adsorption on the crystalline was beneficial for Pt stability. The adsorption energy and bond distance of the adsorbed SO3H on Pt (110), (100), and (111) surfaces were calculated. All the stable configurations were obtained when O from S-O single bond or S was bound to the Pt surface, with the adsorption energy following the trend of (111)F > (100)H > (110)H. This result was consistent with the ECSA experiment, which explained the high electrochemical stability of the sulfonic acid groups-grafted Pt/C catalyst.

Mesoporous sBa-15 silica catalyst functionalized with phenylsulfonic acid groups (SbA-15-ph-So3h) as efficient nanocatalyst for chemoselective thioacetalization of carbonyl compounds

ABSTRACTIn this research a Nano acidic catalyst was prepared and its efficiency on thioacetalization of carbonyl compounds was examined. For this aim we used modified SBA-15 as support, which have been modified by phenolic and sulfonic acid. SBA-15 is a member of mesoporouses. Mesostructures-based properties such as large specific surface, low specific weight, chemical and thermal resistance have been used in different fields such as catalyst, drug delivery, chromatography, microelectronic, separation and purification. Based on our knowledge mesoporoses are ideal catalysts and usually have been used as solid catalyst, which have been modified by organic groups and metal oxides. These types of application are based on the large dispersability of the modifier groups at mesoporouses.

Correction: A mesoporous SBA-15 silica catalyst functionalized with phenylsulfonic acid groups (SBA-15-Ph-SO3H) as a novel hydrophobic nanoreactor solid acid catalyst for a one-pot three-component synthesis of 2H-indazolo[2,1-b]phthalazine-triones and triazolo[1,2-a]indazole-triones

Correction for ‘A mesoporous SBA-15 silica catalyst functionalized with phenylsulfonic acid groups (SBA-15-Ph-SO3H) as a novel hydrophobic nanoreactor solid acid catalyst for a one-pot three-component synthesis of 2H-indazolo[2,1-b]phthalazine-triones and triazolo[1,2-a]indazole-triones’ by Hojat Veisi et al., RSC Adv., 2015, 5, 68523–68530.

A mesoporous SBA-15 silica catalyst functionalized with phenylsulfonic acid groups (SBA-15-Ph-SO3H) as a novel hydrophobic nanoreactor solid acid catalyst for a one-pot three-component synthesis of 2H-indazolo[2,1-b]phthalazine-triones and triazolo[1,2-a]indazole-triones

Phenyl sulfonic acid functionalized mesoporous SBA-15 silica was prepared through the silanization of activated mesoporous SBA-15 with diphenyldichlorosilane followed by silylation and sulfonation.

Improvement of the hydrophilicity of electrospun porous carbon nanofibers by grafting phenylsulfonic acid groups

Electrospun porous carbon nanofibers fabricated by electrospinning and steam activation were functionalized by spontaneous grafting of phenylsulfonic acid (PSA) groups. SEM and Raman observation suggested that modified electrospun nanofibers did not exhibit distinct changes of surface morphology and intrinsic graphitic structure. Nitrogen adsorption showed decrease in surface area and pore volume of modified carbon nanofibers. XPS and elementary analysis were conducted to characterize the surface chemistry of carbon nanofibers. The hydrophilic character was measured by the contact angles and static adsorption isotherms of water. The adsorption isotherms of benzene and butanone showed that the increasing hydrophilicity led to enhancement of adsorption performance for butanone on carbon nanofibers, indicating that the adsorption selectivity to hydrophilic organic compounds was improved.

Synthesis and characterization of new proton conducting hybrid membranes for PEM fuel cells based on poly(vinyl alcohol) and nanoporous silica containing phenyl sulfonic acid

Organic–inorganic hybrid proton exchange membranes were prepared from poly(vinyl alcohol) (PVA) and various amounts of nanoporous silica containing phenyl sulfonic acid groups. These hybrid membranes were prepared via co-condensation of functionalized nanoporous SBA-15 (SBA-ph-SO 3H) as hydrophilic inorganic modifier, glutaraldehyde (GLA) as cross-linking agent in a PVA matrix. These membranes were characterized for their morphology, thermal stability, electrochemical and physicochemical properties using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and water uptake studies. The SBA-ph-SO 3H/PVA composite membranes have a higher water retention and thermal stability than that of Nafion 117, perhaps because of responsibility of both acidic groups and nanoporous structure of silica additive. This work demonstrates the promising potential of new composite membranes for the development of high-performance and high-stability PEM fuel cells with improved proton conductivity.

Modification of hydrophobic/hydrophilic properties of Vulcan XC72 carbon powder by grafting of trifluoromethylphenyl and phenylsulfonic acid groups

Carbon supports (glassy carbon and Vulcan XC72 powder) were modified by electrochemical and spontaneous grafting of phenylsulfonic acid (PSA) or trifluoromethylphenyl (TFMP) groups via diazonium ion reduction. The effectiveness of the grafting was confirmed electrochemically, by XPS measurements and elemental analyses. The hydrophobic or hydrophilic character of carbon surfaces was evidenced by measuring the contact angles of drops of different liquids (water, ethylene glycol and glycerol) in heptane. The surface energy was calculated and it was found, for example, that spontaneous grafting of a glassy carbon surface by PSA groups led to an increase by a factor 20 of the surface energy compared with an unmodified glassy carbon surface. The study of the grafting of such groups on XC72 carbon powder indicated that a very low grafting ratio (in wt%) led to a significant change in the macroscopic properties of the powder. Thermogravimetric analysis coupled with mass spectroscopy measurements (TGA-MS) showed that these grafted layers were thermally stable even in the presence of dispersed platinum nanoparticles. It was shown by cyclic voltammetry that the carbon substrate modification did not affect the electrochemical behavior of platinum catalyst, since the same active surface area was determined on Pt-XC72, Pt-PSA-XC72 and Pt-TFMP-XC72 catalysts.

Hybrid ion-exchange membranes for fuel cells and separation processes

This work reports the preparation and characterization of hybrid membranes cast from dispersions of inorganic fillers in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene solutions. Silica gel, SBA-15 and sepiolite, all of them functionalized with phenylsulfonic acid groups, were used as fillers. For comparative purposes, the performance of composite membranes cast from dispersions of functionalized inorganic fillers in Nafion ® solutions was investigated. Inspection of the texture of the membranes by using SEM techniques shows that the fillers are better dispersed in sulfonated polystyrene-block-poly(ethylene-ran-butylene)-block-polystyrene than in Nafion ®. The value of the water uptake for the membranes prepared from the former polyelectrolyte is in most cases at least three times that measured for hybrid Nafion ® membranes. The conductivity of the membranes was measured at 80 °C by impedance spectroscopy obtaining values of 3.44, 6.90 and 3.54 S m −1 for the hybrid membranes based on the triblock copolymer containing functionalized silica gel, SBA-15 and sepiolite fillers, respectively. These results compare very favourably with those obtained at 80 °C for Nafion ® hybrid membranes containing silica gel, SBA-15 and sepiolite, all of them fuctionalized with phenylsulfonic acid groups, whose conductivities are, 2.84, 6.75 and 3.31 S m −1, respectively. Resistance measurements carried out under controlled humidity conditions show that the conductivity of sulfonated triblock copolymer membranes containing functionalized SBA-15 filler undergoes a rather sharp increase when they are conditioned under an atmosphere of 75%, or larger, relative humidity.

Template-free synthesis of mesoporous phenylsulfonic acid functionalized silica

Mesoporous silica functionalized with phenylsulfonic acid was prepared by a simple template-free co-condensation of tetraethyl orthosilicate (TEOS) and 2-(4-chlorosulfonylphenyl)ethyltrimethoxysilane (CETS) under strong acidic condition. The obtained materials with 3–15 mol% loadings of phenylsulfonic acid were X-ray amorphous, but had large surface areas (420–620 m 2/g) and narrow pore-size distributions (0.3–1.0 nm PSD, estimated from the peak width at half maximum height) with pore diameters in the range of 3.5–5.0 nm. TEOS hydrolysis prior to the addition of CETS was found to be important in order to obtain functionalized silica materials of large mesopores and pore volumes. IR, TG and solid state NMR studies showed that most of the phenylsulfonic acid groups were incorporated into the silica materials without decomposition during the synthesis procedure. Moreover, most of the sulfonic acid sites are accessible by large cations such as tetramethylammonium (TMA +) and tetrabutylammonium (TBA +) ions. The materials were examined as acid catalysts in esterification of acetic acid with methanol and acetalization of chlorobenzaldehyde with methanol. The results showed that the functionalized amorphous silica materials synthesized with TEOS pre-hydrolysis had similar catalytic activities as that of phenylsulfonic acid-functionalized SBA-15, but higher activities than those of the counterparts synthesized without TEOS pre-hydrolysis or the propylsulfonic acid functionalized SBA-15.

Synthesis and catalytic properties of mesoporous ethane-silicas containing phenyl-sulfonic acid group

The synthesis and catalytic properties of the mesoporous ethane-silicas functionalized with phenyl-sulfonic acid were reported. The phenyl-sulfonic acid groups were generated by sulfonation of the mesoporous ethane-silicas functionalized with phenyl groups, which was synthesized via co-condensation of 1,2-bis (trimethoxysilyl)ethane (BTME) and phenyltrimethoxysilane (PTMS) using block co-polymer Pluronic 123 as template in acidic medium. The results of XRD and nitrogen sorption isotherms show that all materials remain their ordered two-dimensional hexagonal mesostructure after sulfonation. The existence of phenyl-sulfonic acid groups was confirmed by UV-Raman spectroscopy, acid–base titration method and ICP-AES. The acid exchange capacity of these materials is in the range of 0.49–0.86 mmol H + g −1. The sulfonated materials can effectively catalyze the condensation of phenol with acetone for the production of Bisphenol-A and the Claisen-Schmidt condensation of acetophenone with benzaldehyde to form chalcone. The catalytic results show that the catalytic activity of the mesoporous materials is not only affected by the amount of the phenyl-sulfonic acid group, but also by the structural order of the mesoporous materials.

Retention behavior of carboyxlic acids on highly cross-linked poly(styrene-divinylbenzene)-based and silica-based cation exchangers

A highly cross-linked porous poly(styrene-divinylbenzene) resin was reacted with sulfuric acid to give strong cation-exchange resins with capacities from 0.2 to 1.9 mequiv./g. The retention behavior of mono- and dicar☐ylic acids on these resins was compared with results obtained from silica-based cation exchangers functionalized with alkylsulfonic acid or phenylsulfonic acid groups. The contribution of different retention mechanisms like ion exclusion, hydrophobic interaction and adsorption to the separation of the analytes on these chromatographic supports was discussed. Additionally the applicability of silica-based cation exchangers was tested in the field of silage analysis.