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Selective cleavage of C–C bonds can be a valuable tool for various applications including polymer degradation and biomass utilization. Performing chemical transformations involving C–C bond cleavag...

As an essential component in efficient perovskite photovoltaics (PPVs), hole transport materials (HTMs) that meet the intricate requirements for next-generation charge transport layers have recently been of immense interest. Specifically, functionally tailored HTMs that aid in mitigating charge transport limitations and interfacial defects and thereby enhance the performance of both indoor and outdoor PPVs are being sought after. Herein, we developed a novel graft-type polymer composed of a benzo[1,2-b:4,5:b′]dithiophene-based main chain and poly(ethylene glycol) (PEG) side chains as an efficient dopant-free HTM for PPVs. Through a systemized tailoring of the contents of the side chains, we were able to control the hole transport and interfacial passivation abilities of the graft-type polymeric HTM. The polymeric HTM with an optimized PEG side chain exhibited a higher hole mobility, a reduced amount of interfacial traps, and an enhanced device stability compared to the control polymeric HTM. The PPVs capped with the optimized graft-type polymeric HTM demonstrated remarkably high power conversion efficiencies up to 38.2% and 21.7% under 1000 lux LED and AM 1.5 solar illuminations, respectively.

A Spiro fluorene-based dopant-free hole-transporting material denoted as Spiro-IA has been designed and developed from inexpensive starting materials with high yield via a simple synthetic approach for application in perovskite solar cells (PSCs). The unit cost of Spiro-IA can be as low as 1/9th that of the conventional Spiro-OMeTAD. Moreover, Spiro-IA shows good solubility in different organic solvents, e.g. CHCl3, acetone, EtOH, and DMF, and showed favorable charge-transport ability and greater photocurrent density compared to Spiro-OMeTAD. The UV absorption/emission spectra of Spiro-IA (λmax = 430 nm, Emax = 601 nm) are red shifted compared to those of Spiro-OMeTAD (λmax = 388 nm, Emax = 414 nm) with larger stokes shift values (171 nm) which helps suppress the loss of incident photons absorbed by the HTM and is more beneficial for improving the performance of PSCs. Optical and electrochemical studies show that Spiro-IA fulfilled the basic requirements of the hole transfer and electron regeneration process in the fabricated devices. PSCs fabricated (surface area = 1.02 cm2) with dopant-free Spiro-IA achieved a maximum power conversion efficiency (PCE) of 15.66% (JSC = 22.14 mA cm−2, VOC = 1.042 V, FF = 0.679%), which was comparable to that of the most commonly used Li-doped Spiro-OMeTAD (PCE = 15.93%, JSC = 20.37 mA cm−2, VOC = 1.057 V, FF = 0.74%) and surpassed that of the dopant-free Spiro-OMeTAD (PCE = 9.34%). Additionally, the PSCs based on dopant-free Spiro-IA achieved outstanding long-term stability and favorable conductivity (σ = 2.104 × 10−4 S cm−1) compared to those based on Spiro-OMeTAD (σ = 9.00 × 10−8 S cm−1). DFT studies were performed using Gaussian 09 at the B3LYP/6-31G (d/p) level to investigate their electron cloud delocalization in HOMO/LUMO levels. These results showed that Spiro-IA could be a promising candidate for low-cost PSC technology and has a great chance to supersede the expensive Spiro-OMeTAD.

Conventional, high-efficiency, hybrid organic–inorganic perovskites (e.g., methylammonium lead iodide (MAPbI3) and formamidinium lead iodide (FAPbI3)) having ammonium-based organic cations exhibit poor moisture stability mainly due to the effective hydrogen bonding interaction of nitrogen in the ammonium-based cations with water molecules. Recently, a sulfonium-based cation, trimethylsulfonium (TMS+), has attracted growing attention for the development of moisture-stable hybrid perovskite solar cells (PSCs). This research investigated the photovoltaic performance of trimethylsulfonium lead triiodide (TMSPbI3) based PSCs and their moisture stability both experimentally and theoretically. The results revealed that TMSPbI3 exhibited a relatively large optical band gap (Eg = 2.32 eV) and high absorption coefficient (α = 2.30 × 104 cm−1 at 500 nm) with a hexagonal one-dimensional crystal structure. The PSCs with a device structure of FTO/c-TiO2/m-TiO2/TMSPbI3/CuSCN/Au exhibited a power conversion efficiency (PCE) of 2.22% with no hysteresis in the I–V curve, and high moisture stability at ambient temperature (25 ± 3 °C, ca. 50% relative humidity) with a PCE loss of only ca. 4.6% after 500 h. This result could be attributed to the absence of the hydrogen bonding interaction of TMS+ with water molecules, leading to the effective stabilization of TMSPbI3 compared to MAPbI3 and FAPbI3, verified by density functional theory calculations.

Ramie leaf (Boehmeria nivea L.) is rich in cellulose, polyphenol compounds, vitamin C, and minerals. The leaves of this plant, which are used for medicinal purposes, have long been reported to have anti‐inflammatory, antioxidant, anticolitis, and antidiabetic effects. We investigated the protective effects of ramie leaf ethanol extract (RLE) against loperamide‐induced constipation and oxidative stress in rats. Male Sprague‐Dawley rats were administered 200 or 400 mg/kg body weight of RLE (RLEL and RLEH groups) by gavage, while normal (NOR) and control (CON) rats received saline. Loperamide (4.0 mg/kg, twice per day) was injected subcutaneously to induce constipation in RLEL, RLEH, and CON groups. Total fecal number, wet weight, and water content decreased, while the total number of loperamide‐induced fecal pellets in the distal colon increased with administration of RLE in a dose‐dependent manner. Gastrointestinal transit time was more greatly reduced in RLE‐treated groups than in the CON group. Serum total cholesterol (TC) level, as well as alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activity, was significantly lower in both RLEL and RLEH groups compared with the CON group. Intestinal mucosa malondialdehyde (MDA) and hydrogen peroxide (H2O2) production decreased significantly in a dose‐dependent manner in the RLE‐treated groups. Loperamide decreased the antioxidant enzyme activity, including that of superoxide dismutase (SOD) and glutathione peroxidase (GSH‐Px), while RLE administration increased the antioxidant activity. These results suggest that RLE exerts potent laxative and antioxidant effects in model rats with loperamide‐induced constipation.

Oxide scales often formed on the surface of stainless steel, and it is of high interest to descale the surface oxide effectively and environment-friendly during steel smelting and engineering processing. It is generally done by treating the oxide layer under strong and harsh mixed acid (HNO3 + HF) conditions or in a strong molten salt (NaOH + NaNO3) environment at high temperatures, while the generation of very harmful and environmentally hazardous gases, such as NO x , is inevitable. A novel, simple, fast, and environment-friendly electrochemical method at ambient temperature is proposed in this research to remove the oxide scale from the stainless steel surface using an ionic liquid with a small amount of HCl. It was found that the optimized electrochemical anodization treatment in an ionic liquid environment could significantly improve the descaling efficiency at least 50 times faster than the simple passive and slow dissolution in a mixture of an ionic liquid and a concentrated acid.

Luminescent solar concentrators (LSCs) provide a transformative approach to integrating photovoltaics into a built environment. In this paper, we report thin-film LSCs composed of intramolecular charge transfer fluorophore (DACT-II) and discuss the effect of two polymers, polymethyl methacrylate (PMMA), and poly (benzyl methacrylate) (PBzMA) on the performance of large-area LSCs. As observed experimentally, DACT-II with the charge-donating diphenylaminocarbazole and charge-accepting triphenyltriazine moieties shows a large Stokes shift and limited re-absorption losses in both polymers. Our results show that thin-film LSC (10 × 10 × 0.3 cm3) with optimized concentration (0.9 wt%) of DACT-II in PBzMA gives better performance than that in the PMMA matrix. In particular, optical conversion efficiency (ηopt) and power-conversion efficiency (ηPCE) of DACT-II/PBzMA LSC are 2.32% and 0.33%, respectively, almost 1.2 times higher than for DACT-II/PMMA LSC.

In this study, we report a new BODIPY-based design, called the cross-conjugated design, that takes advantage of the α- and β-position functionalization of the BODIPY core. After synthesis, and compared to a more standard BODIPY dye, using similar functional groups and based on a horizontal design, called h-BOD, the new cross-conjugated BODIPY dye (cc-BOD) exhibits clearly the highest conjugation and light harvesting properties. Consequently, when used as photosensitizers in dye-sensitized solar cells (DSSCs), an impressive improvement of power conversion efficiency (PCE) has been observed, with a PCE of 6.02% with broad incident photon to current conversion efficiency (IPCE) for cc-BOD, compared to only 3.7% for h-BOD. Moreover, by co-sensitizing a DSSC with the two complementary absorbing dyes h-BOD and cc-BOD, we further improved the PCE up to 6.2%.

A tetrathiafulvalene derivative containing two amide units for intermolecular hydrogen bonds (Bis-amide-TTF) was found to form supramolecular assemblies, in which intermolecular TTF cores were stacked with each other. The electrical conductivity of Bis-amide-TTF-based film was 1.28 × 10 - 5 S c m - 1 , which was greater than that of spiro-OMeTAD doped with t-butylpyridine and bis(trifluoromethane)sulfonimide lithium salt ( 8.37 × 10 - 6 S c m - 1 ). Bis-amide-TTF was applied as a hole transport material (HTM) for perovskite solar cells (PSCs). The Bis-amide-TTF film has a deeper HOMO level than that of spiro-OMeTAD, leading to an increased open-circuit voltage of the PSCs. The power conversion efficiency of 14.5% with a short-circuit current density (Jsc) of 19.8 mA cm−2, an open-circuit voltage (Voc) of 1.11 V, and a fill factor (FF) of 66% was achieved for PSCs fabricated with the dopant-free Bis-amide-TTF-based HTM, which was comparable to that obtained with spiro-OMeTAD with the dopants (15.5%).

Monomeric perylene diimide (PDI) small molecules display a high absorption coefficient and crystallinity in solid-state thin films due to strong π-π interactions between the molecules. To take advantage of these exciting properties of PDIs, N,N'-bis(1-ethylpropyl)perylene-3,4,9,10-tetracarboxylic diimide (EP-PDI) was mixed with a binary blend of PTB7 and PC71 BM to fabricate an efficient ternary blend, which were in turn used to produce organic photovoltaic (OPV) devices well suited to indoor applications (PTB7=poly({4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl}{3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl}), PC71 BM=[6,6]-phenyl-C71 -butyric acid methyl ester). We varied the PC71 BM/EP-PDI weight ratio to investigate the influence of EP-PDI on the optical, electrical, and morphological properties of the PTB7:PC71 BM:EP-PDI ternary blend. Compared with the reference PTB7:PC71 BM binary blend, the ternary blends showed strong optical absorption in the wavelength range in which the spectra of indoor LED lamps show their strongest peaks. The addition of EP-PDI to the binary blend was found to play an important role in altering the morphology of the blend in such a way as to facilitate charge transport in the resulting ternary blend. Apparently, as a result, the optimal PTB7:PC71 BM:EP-PDI-based inverted OPV device exhibited a power conversion efficiency (PCE) of 15.68 %, a fill factor (FF) of 68.5 %, and short-circuit current density (JSC ) of 56.7 μA cm-2 under 500 lx (ca. 0.17 mW cm-2 ) indoor LED light conditions.

In this work, a simple and one-step solvothermal method has been developed for directly growing three-dimensional flower-like cobalt sulfide (CoS) on the fluorine-doped tin oxide coated glass substrate (FTO) for the counter electrode in the dye sensitized solar cell. The electroctalytic activity of the CoS@FTO towards the I3− to I− reduction exhibited almost similar electrocatalytic properties to the Pt-based counter electrode. The dye-sensitized solar cell (DSSC) assembled with CoS@FTO counter electrode attained almost similar photovoltaic performance (5.64%) to that of the DSSC with Pt@FTO counter electrode (5.9%) under 1 sun illumination. The adhesion stability of the CoS deposited at FTO was also studied using strong adhesive tape test, and the results show that after the strong adhesive tape test, the CoS@FTO retained almost 95% of the coating. The similar and comparative performance of the CoS@FTO to the Pt@FTO may be due to the high surface area originating from the 3D flower-like morphology, and the excellent electrocatalytic activity of the CoS.

A novel electrochemical aptasensor based on gold nanoparticles decorated on boron nitride nanosheets (AuNPs/BNNSs) for the sensitive and selective detection of myoglobin (Mb) is reported. BNNSs were chemically synthesized by a low-cost and simple hydrothermal method. They were deposited onto the fluorine-doped tin oxide (FTO) electrode by a spin-coating method. Subsequently, AuNPs were chemically deposited onto the BNNS/FTO electrode by a seed-mediated chemical reduction method, with an average particle size of approximately 10 nm. The AuNPs/BNNSs/FTO electrode was used as a transducer to immobilize a thiol-functionalized DNA aptamer (Apt) via the covalent interaction of Au–S for the specific binding of Mb. [Fe(CN)6]3-/4- was used as a redox probe to monitor the oxidation current variation upon the binding of Mb with varying concentrations onto the sensor surface. The Apt/AuNPs/BNNSs/FTO sensor shows a high signal response for Mb with a detection limit of 34.6 ng/mL and a dynamic response range of 0.1–100 µg/mL. It is a promising candidate for point-of-care diagnosis in real samples. This strategy could make possible the application of other 2D materials with wide bandgaps for the development of biosensors.

The steric shielding offered by sensitizers on semiconducting surfaces as a result of branching in the dyes used offers the less utilization of semiconducting substrate sites during device fabrication in dye-sensitized solar cells (DSSCs). This work proposes a strategy to increase the coverage through the utilization of small molecules which have the ability to penetrate into the sites. The small molecules play the dual role of vacancy filling and sensitization, which can be viewed as an alternative to co-sensitization also. Hence, we show for the first time ever that the co-adsorption of catechol with Z907 as a sensitizer enhances the electron density in the photo-anode by adsorbing on the vacant sites. Catechol was subsequently adsorbed on TiO2 after Z907 as it has a stronger interaction with TiO2 owing to its favorable thermodynamics. The reduced number of vacant sites, suppressed charge recombination, and enhanced spectral response are responsible for the improvement in the PCEs. Quantitatively, both organic and aqueous electrolytes were used and the co-sensitized DSSCs had PCE enhancements of 7.2 and 60%, respectively, compared to the control devices.

This aim of this study was to investigate the potential beneficial effects of rice bran powder, fermented by Weissella koreensis DB1 isolated from kimchi, to protect against obesity and dyslipidemia induced by a high-fat and high-cholesterol diet, in a mouse model. Male mice were fed a modified AIN-93M diet containing high fat/high-cholesterol (HFCD), or same diet supplemented with non-fermented rice bran powder (HFCD-RB) or fermented rice bran powder (HFCD-FRB) for 10 weeks. In the HFCD-FRB group, body weight, liver and white fat pads weights, triglyceride (TG), total cholesterol (TC), non-high-density lipopreotein cholesterol (non-HDL-C), insulin, glucose and leptine levels in serum, TG levels and the ratio of fat droplets in the liver, TG levels and fat cell size in adipose tissue were decreased, and (high-density lipopreotein cholesterol) HDL-C and adiponectin levels in serum were increased, compared with the HFCD group. The HFCD-FRB group had significantly lower CCAAT-enhancer-binding potein α (C/EBPα), sterol regulatory element-binding transcription protein-1c (SREBP-1c), fatty acid synthase (FAS), and acetyl CoA carboxylase (ACC) gene expression when compared to the HFCD group. The anti-obesity and hypolipidemic effects were marginally greater in the HFCD-FRB group than in the HFCD-RB group. These results suggest that fermented rice bran powder by Weissella koreensis DB1 may have potential beneficial effects on the obesity-related abnormalities and the dysfunction of lipid metabolism.

Soybean koji refers to steamed soybeans inoculated with microbial species. Soybean fermentation improves the health benefits of soybeans. Obesity is a serious health concern owing to its increasing incidence rate and high association with other metabolic diseases. Therefore, we investigated the effects of soybean and soybean koji on high-fat diet-induced obesity in rats. Five-week-old male Sprague-Dawley rats were randomly divided into four groups (n = 8/group) as follows: (1) regular diet (RD), (2) high-fat diet (HFD), (3) HFD + steamed soybean (HFD+SS), and (4) HFD + soybean koji (HFD+SK). SK contained more free amino acids and unsaturated fatty acids than SS. In a rat model of obesity, SK consumption significantly alleviated the increase in weight of white adipose tissue and mRNA expression of lipogenic genes, whereas SS consumption did not. Both SS and SK reduced serum triglyceride, total cholesterol, and low-density lipoprotein cholesterol levels, and increased high-density lipoprotein cholesterol levels. SS and SK also inhibited lipid accumulation in the liver and white adipose tissue and reduced adipocyte size. Although both SS and SK could alleviate HFD-induced dyslipidemia, SK has better anti-obesity effects than SS by regulating lipogenesis. Overall, SK is an excellent functional food that may prevent obesity.

We investigated conducting poly(thionine) (PTH) films prepared by single-step and double-step electrochemical methods (PTH-S and PTH-D, respectively) on the surface of a glassy carbon electrode (GCE) for the detection of dopamine (DA) with varying sensitivity. Electrochemical and spectroscopic analysis revealed that both PTH films have identical chemical structures, but the sensitivity of DA detection was significantly dependent on the polymerization conditions. A simple variation of the electropolymerization conditions dramatically changed the catalytic activity of the PTH films towards the oxidation of DA in the presence of ascorbic acid (AA) and uric acid (UA) as well as the PTH formation mechanism. PTH-D was found to have a higher surface charge than PTH-S, and also showed a sensitivity enhancement for DA detection of up to one order of magnitude compared to PTH-S.

Random polythiophene polymers are characterized by the arbitrary sequences of monomeric units along polymer backbones. These untailored orientations generally result in the twisting of thiophene rings out of the conjugation planarity in addition to steric repulsions experienced among substituted alkyl chains. These tendencies have limited close polymer packing, which has been detrimental to charge transport in these moieties. To ameliorate charge transport in these classes of polymers, we make use of simple Stille coupling polymerization to synthesize highly random polythiophene polymers. We induced a positive microstructural change between polymer chains by attuning the ratio between alkyl-substituted and nonalkyl-substituted monomer units along the backbones. The optimized random polythiophene was found to have enhanced intermolecular interaction, increased size of crystallites, and stronger tendency to take edge orientation compared with both regiorandom and regioregular poly(3-hexylthiophene) polymers. Incorporation of the optimized random polythiophene as an active material in solid-state electrolyte-gated organic field-effect transistors exhibited better performance than the control device using regioregular poly(3-hexylthiophene), with a high hole mobility up to 4.52 cm

This study aimed at investigating the anti-obesity and anti-dyslipidemic effects of Stachys sieboldii Miq. root (SS) powder in rats following a high-fat and high-cholesterol (HFC) diet for 6 weeks. Thirty-two Sprague&ndash, Dawley rats were fed one of the following diets: a regular diet (RD), HFC, HFC supplemented with 3% SS (HFC + 3SS) or HFC supplemented with 5% SS (HFC + 5SS). Following an HFC diet increased body weight (BW) gain (p &lt, 0.001) and the food efficiency ratio (FER, p &lt, 0.001), however, SS consumption gradually prevented the HFC-induced BW gain (p &lt, 0.001) and increase in FER (p &lt, 0.01). The HFC diet resulted in increased liver size (p &lt, 0.001) and total adipose tissue weight (p &lt, 0.001), whereas the SS supplementation decreased hepatomegaly (p &lt, 0.05) and body fat mass (p &lt, 0.001). SS consumption prevented the increased activities of serum alanine aminotransferase (ALT, 0.001), aspartate aminotransferase (AST, 0.001), alkaline phosphatase (ALP, 0.01 in HFC + 5SS) and lactate dehydrogenase (LDH, 0.001 in HFC + 5SS) induced by the HFC diet (p &lt, 0.001). The SS supplementation improved lipid profiles in the circulation by lowering triglyceride (TG, 0.01), total cholesterol (TC, 0.001) and non-HDL cholesterol (non-HDL-C, 0.001) levels, as well as the atherogenic index (p &lt, 0.01) and cardiac risk factor (p &lt, 0.01). The lipid distribution in the liver (p &lt, 0.05) and white adipose tissues (WAT, 0.001) of the HFC + SS diet-consuming rats was remarkably lower than that of the HFC diet-consuming rats. The average size of the epididymal adipose tissue (p &lt, 0.001) was significantly lower in the HFC + SS diet-fed rats than in the HFC diet-fed rats. The fecal lipid (&gt, 3% SS, 0.001) and cholesterol (5% SS, 0.001) efflux levels were significantly elevated by the SS supplementation compared to those measured in the RD or HFC diet-fed groups. In addition, the hepatic lipid and cholesterol metabolism-related gene expressions were affected by SS consumption, as the hepatic anabolic gene expression (Acc, 0.001, Fas, 0.001 and G6pdh, 0.01) was significantly attenuated. The HFC + 5SS diet-fed rats exhibited elevated hepatic Cyp7a1 (p &lt, 0.001), Hmgcr (p &lt, 0.001) and Ldlr (p &lt, 0.001) mRNA expression levels compared to the HFC diet-fed rats. These results suggest that SS may possess anti-adipogenic and lipid-lowering effects by enhancing lipid and cholesterol efflux in mammals.

This study aimed to investigate the potential of cabbage-apple juice, fermented by Lactobacillus plantarum EM isolated from kimchi, to protect against obesity and dyslipidemia that are induced by a high-fat diet in a rat model. Male rats were fed a modified AIN-93M high-fat diet (HFD), the same diet supplemented with non-fermented cabbage-apple juice, or the same diet supplemented with fermented cabbage-apple juice for eight weeks. In the HFD-fermented cabbage- apple juice administered groups the following parameters decreased: body weight, liver and white fat pad weights, serum triglyceride (TG), total cholesterol (TC), LDL-cholesterol, insulin, glucose and leptin levels, TG levels, while HDL-C and adiponectin levels in serum increased as compared with the HFD group. The HFD-fed rats that were supplemented with fermented cabbage-apple juice exhibited significantly lower fatty acid synthase (FAS), acetyl-CoA carboxylase (ACC), and malic enzyme gene expression levels when compared to the exclusively HFD-fed rats. The anti-obesity and hypolipidemic effects were marginally greater in the fermented juice administered group than in the non-fermented juice administered group. These results suggest that cabbage-apple juice&mdash, especially fermented cabbage-apple juice&mdash, might have beneficial effects on lipid metabolism dysfunction and obesity-related abnormalities. However, further studies are necessary for analyzing the biochemical regulatory mechanisms of fermented juice for obesity amelioration and lipid metabolic homeostasis.

Sn-based perovskite solar cells (PSCs) featuring high performance and long-term stability are very challenging because Sn2+ is relatively prone to oxidation. Here, we have performed coadditive engineering with 5-ammonium valeric acid iodide (5-AVAI) for FASnI3-based perovskite films. From the morphological, structural, and elemental analyses, we observed that 5-AVAI affects the crystal growth of perovskites through its hydrogen bond with I– of the SnI64– octahedral. As a result, pinhole-free homogeneous and stable Sn-based perovskite films form over a large area with lower Sn4+ content. This made us able to enhance the power conversion efficiency (PCE) for Sn-based PSCs up to 7% in a 0.25 cm2 aperture area. Most importantly, the 5-AVAI added PSCs showed a record stability and maintained their initial PCE under 1 sun continuous illumination at maximum power point tracking for 100 h.

Indoor solar cells are an attractive option to install in buildings to harvest the energy emitted by indoor lighting. They can be implemented as a stand-alone grid, or as part of an integrated energy harvesting unit. Previous research has utilized amorphous silicon and dye-sensitized solar cells for power generation from a fluorescent light source. In our study, we evaluated the applicability of a poly (3-hexylthiophene):indene-C60 bisadduct solar cell to harvest the light spectrum from an indoor light-emitting diode (LED). Because the absorption peak of poly (3-hexylthiophene) overlaps the LED spectrum peak, it serves as a good candidate for indoor light harvesting under an LED source. We have extracted the power conversion efficiency of the solar cell under different LED illuminance values, such as 200, 800, 1000, and 2000 lx. With the help of finite-difference time domain simulations, we optimized the solar device structure for each illuminance. The results detailed in this article were intended to assess the applicability of organic solar cells as indoor photovoltaics, and to provide a methodology to optimize the photovoltaic structure to maximize its efficiency.

Thin film of metallic Cu nanoparticles was synthesized by a one-pot chemical reduction method at ambient temperature. Cu(II) acetate monohydrate and hydrazine monohydrate were used as precursor and reducing agent without additional surfactants to form uniform layer of Cu nanoparticle layer on a glass substrate (Cu/G). The XRD and the effectiveness of the electrocatalytic and catalytic properties of the Cu/G have been applied for an amperometric detection of glucose and for the chemical reduction of 4-nitrophenol. The former exhibited the detection limit as low as 2.47 μM with a linear range of 0.01–0.2 mM, while the latter showed the efficient catalytic activity with a high rate constant of 0.503/min. The current method suggested in this work might be useful for the fabrication of glass-based Cu nanoparticles electrodes for industrial and biomedical applications.

An organo-sulfur compound, 5-methylthio-1,3,4-thiadiazole-2-thiol and its oxidized dimer 5-methylthio-1,3,4-thiadiazolium disulfide dication are used as a novel and universal redox couple in both dye-sensitized and quantum-dot sensitized solar cells, in conjunction with a conducting poly(3,4-ethylenedioxythiophene) counter electrode. The 5-methylthio-1,3,4-thiadiazole-2-thiol/5-methylthio-1,3,4-thiadiazolium disulfide dication redox couple is low-cost and easily processable, and exhibits non-absorption of visible light, showing improved redox behavior at an electrochemically deposited poly(3,4-ethylenedioxythiophene) counter electrode. Its redox potential is ca. 60 mV negatively and ca. 170 mV (vs. normal hydrogen electrode) positively positioned than those of iodide/tri-iodide and polysulfide electrolytes, respectively. The maximum power conversion efficiency of (3.55 and 1.20) % is obtained in dye and quantum-dot sensitized solar cells, respectively, sensitized by 5-[[4-[4-(2, 2-Diphenylethenyl) phenyl]-1,2,3,3a,4,8b hexahydrocyclopent [b] indol-7-yl] methylene]-2-(3-octyl-4-oxo-2-thioxo-5-thiazolid dye and CdS-quantum dot, respectively, together with the optimized poly(3,4-ethylenedioxythiophene) counter electrode. These results clearly outperform the performance of identical dye and quantum-dot sensitized solar cells with Pt and Cu2S-counter electrodes. Thus, this new redox couple and poly(3,4-ethylenedioxythiophene) counter electrode pair is expected to offer a promising and universal alternative to the conventional iodide/tri-iodide and polysulfide electrolytes for sensitization-based solar cells.

The stability of perovskite solar cells (PSCs) are critically related to the perovskite crystal morphology and film quality, hence controlling the perovskite film formation is one of the key concerns. In this study, we have used four anti-solvents- toluene, chlorobenzene, p-xylene and ether to fabricate high quality CH3NH3PbI3 perovskite films. We investigated the surface morphology, optical and structural properties of the corresponding perovskite films. Consequently, PSCs with variation of these anti-solvents were fabricated and the respective photovoltaic performances over a period of 30 days in dark and under air mass 1.5G sunlight conditions have been observed. Our analyses onto the post fabrication of PSCs highlight that, the perovskite films formed by toluene, chlorobenzene and p-xylene treatment results in high efficient and stable PSCs in dark. Interestingly, the ether treated PSC had no photovoltaic response after 10 days. The toluene and chlorobenzene treated PSCs showed stable device performance and retained 90% of their initial power conversion efficiency even after 30 days light soaking. The p-xylene treated PSCs showed unstable performance during the same light soaking period.

Low temperature processed Perovskite solar cells (PSCs) are popular due to their potential for scalable production. In this work, we report reduced Graphene Oxide (r-GO)/copper (I) thiocyanate (CuSCN) as an efficient bilayer hole transport layer (HTL) for low temperature processed inverted planar PSCs. We have systematically optimized the thickness of CuSCN interlayer at the r-GO/MAPbI3 interface resulting in bilayer HTL structure to enhance the stability and photovoltaic performance of low temperature processed r-GO HTL based PSCs with a standard surface area of 1.02 cm2. With matched valence band energy level, the r-GO/CuSCN bilayer HTL based PSCs showed high power conversion efficiency of 14.28%, thanks to the improved open circuit voltage (VOC) compared to the only r-GO based PSC. Moreover, enhanced stability has been observed for the r-GO/CuSCN based PSCs which retained over 90% of its initial efficiency after 100 h light soaking measured under continuous AM 1.5 sun illumination.

BACKGROUND/OBJECTIVES Obesity is a global health problem of significant importance which increases mortality. In place of anti-obesity drugs, natural products are being developed as alternative therapeutic materials. In this study, we investigated the effect of Brassica juncea L. leaf extract (BLE) on fat deposition and lipid profiles in high-fat, high-cholesterol diet (HFC)-induced obese rats. MATERIALS/METHODS Male Sprague-Dawley rats were divided into four groups (n = 8 per group) according to diet: normal diet group (ND), high-fat/high-cholesterol diet group (HFC), HFC with 3% BLE diet group (HFC-A1), and HFC with 5% BLE diet group (HFC-A2). Each group was fed for 6 weeks. Rat body and adipose tissue weights, serum biochemical parameters, and tissue lipid contents were determined. The expression levels of mRNA and proteins involved in lipid and cholesterol metabolism were determined by reverse transcription polymerase chain reaction and western blot analysis, respectively. RESULTS The HFC-A2 group showed significantly lower body weight gain and food efficiency ratio than the HFC group. BLE supplementation caused mesenteric, epididymal, and total adipose tissue weights to decrease. The serum levels of triglyceride, total cholesterol, and low-density lipoprotein cholesterol were significantly reduced, and high-density lipoprotein cholesterol was significantly increased in rats fed BLE. These results were related to lower glucose-6-phosphate dehydrogenase, acetyl-coA carboxylase, and fatty acid synthase mRNA expression, and to higher expression of the cholesterol 7α-hydroxylase and low density lipoprotein-receptor, as well as increased protein levels of peroxisome proliferator-activated receptor α. Histological analysis of the liver revealed decreased lipid droplets in HFC rats treated with BLE. CONCLUSIONS Supplementation of HFC with 3% or 5% BLE inhibited body fat accumulation, improved lipid profiles, and modulated lipogenesis- and cholesterol metabolism-related gene and protein expression.

Nanostructured copper–cobalt based spinel [(Cu0.30Co0.70)Co2O4] was employed as an electrocatalyst in the hydrogen peroxide (H2O2) reduction reaction (HRR). Both nanoparticles and nanoneedles co-existed in the (Cu0.30Co0.70)Co2O4 spinel, which exhibited a high intrinsic electrical conductivity and surface-to-volume ratio, resulting therefore in a large electrochemically active surface area for the HRR. In addition, (Cu0.30Co0.70)Co2O4 showed an onset potential at approximately −0.14 V in the HRR, with a limiting current density of ∼104 mA/cm2 at −0.43 V. The synthesised material followed the direct HRR pathway and exhibited good stability. In addition, the HRR activity of (Cu0.30Co0.70)Co2O4 was comparable to that of commercial Pt/C electrodes. The present results therefore demonstrate the significant potential of (Cu0.30Co0.70)Co2O4 for future applications in fuel cells as a cathode catalyst.

This review summarizes the results of studies on the selective dissolution and extraction of Fe, Cr, Cu, and Zn by ionic liquids, as an alternative to the use of conventional molten salts or pickling agents, for various types of steel. Ionic liquids are classified according to the metals, metal ions, and metal oxides by which they can be extracted or dissolved. The results of the metal extraction efficiency per unit time presented in the literature are summarized in a simple unified graphic format. This provides a comparative understanding of the most efficient ionic liquid for the extraction of specific metals.

In this study, we compared the antiobesity effects between gochujangs prepared using different koji products and Tabasco hot sauce in rats fed a high-fat diet (HFD). Male Sprague-Dawley rats were fed HFD containing four different types of 10% gochujang powder or 0.25% commercial Tabasco sauce powder for 8 weeks. The body weight gain, liver and epididymal and mesenteric fat pad weights, serum leptin levels, and lipogenesis-related mRNA levels of HFD-gochujang supplementation groups were significantly decreased compared with those of the HFD group. In addition, gochujang supplement significantly reduced adipocyte size; hepatic triglyceride and total cholesterol levels; the occurrence of fatty liver deposits and steatosis by inhibiting lipogenesis through downregulation of fatty acid synthase, acetly-CoA carboxylase, and glucose-6-phosphate-dehydrogenase. These effects were greater in the gochujang-supplemented groups than the Tabasco hot sauce-supplemented group. The gochujang prepared by nutritious giant embryo rice koji and soybean koji was most effective in terms of antiobesity effects, compared with the other tested gochujangs. In gochujangs, the antiobesity effects are mediated by high levels of secondary metabolites such as isoflavone, soyasaponin, capsaicin, and lysophosphatidylcholine. The current results indicated that the gochujang products have the potential to reduce fat accumulation and obesity.

Dye sensitized solar cells (DSSCs) were co-sensitized with three custom molecularly engineered organic dyes containing butyloxyl chain induced dye (Y1), boron dipyrromethene (bodipy) dye (TP2A), and squaraine (SQ) ring configured dye (HSQ4). The individual power conversion efficiencies of the DSSCs sensitized with Y1, TP2A and HSQ4 sensitizers were 3.44%, 4.26% and 5.78%, respectively. Co-sensitized TP2A + HSQ4 dyes at a 2 : 1 molar ratio showed an efficiency of 7.02%. Further addition of Y1 dye with optimal TP2A + HSQ4 increased the VOC from 0.580 V to 0.605 V. The co-sensitized Y1 + TP2A + HSQ4 based DSSCs showed a new optimal efficiency (η) of 7.48%. This is the highest efficiency recorded for DSSCs based on co-sensitization of triple organic dyes. Intensity modulated photovoltage spectroscopy further confirms the longer lifetime of co-sensitized Y1 + TP2A + HSQ4 compared to that of each individual TP2A and HSQ4 and co-sensitized TP2A + HSQ4 dye.

Organosulfonium cations have attracted growing attention over conventional organoammonium cations for the development of moisture-stable hybrid organic–inorganic metal halide perovskite solar cells (PSCs). Herein, the synthesis of a moisture-stable trimethylsulfoxonium lead triiodide ((CH3)3SOPbI3 or TMSOPbI3) perovskite is described via a two-step solution process in an aqueous medium. The synthesized TMSOPbI3 exhibits a one-dimensional nanorod array with an optical bandgap of 2.30 eV and a hexagonal crystal structure. In addition, the fabricated fluorine-doped tin oxide/compact-TiO2/mesoporous-TiO2/TMSOPbI3/CuSCN/Au PSC device generates a maximum power conversion efficiency (PCE) of 2.23% with a good moisture stability at ambient temperature and relative humidity (50%) with no PCE loss during 336 h and no change in the crystal structure during 50 days. The high moisture stability of the device is attributed to the absence of hydrogen bonding between the trimethylsulfoxonium (TMSO+) cation and the H2O molecules along with strong electrostatic interactions between the TMSO+ and [PbI6]4- polyhedra in the TMSOPbI3. This research has demonstrated that TMSO+ is suitable for fabricating a stable perovskite-like material with good optoelectronic properties and is a promising material for practical applications.

This study aimed to compare the effects of spirit vinegar and four types of natural fermented vinegar products (apple vinegar, brown rice vinegar, lemon vinegar, and balsamic vinegar) on the differentiation of 3T3-L1 cells and obesity in rats fed a high-fat diet (HFD). Vinegar inhibited the accumulation of lipid droplets during the differentiation of 3T3-L1 cells. Body weight gains, visceral fat pad weights, serum leptin and triglyceride levels, and hepatic lipogenic enzyme mRNA levels were significantly decreased in the HF-vinegar administered groups compared with those in the HF group. Furthermore, oral administration of vinegars significantly reduced the occurrence of fatty liver deposits and steatosis, and inhibited the HF diet-induced increase in adipocyte size. The anti-obesity and lipid-lowering effects were slightly greater in the HF-natural fermented vinegar groups than in the HF-spirit vinegar group. Apple vinegar had the strongest anti-obesity effects in 3T3-L1 cells and obese rats compared with the other tested vinegars. These findings indicated that vinegar administration may have potential for improving some obesity-related parameters in 3T3-L1 cells and obese rats.

This study examined the laxative effects of mulberry leaf extract (MLE) fermented by lactic acid bacteria (LAB), which contains high levels of polyphenolic and flavonoid compounds, against loperamide-induced constipation in rats. Sprague-Dawley rats were divided into a normal group (N) and three experimental groups; loperamide treated group (C), loperamide and LAB-fermented MLE 300 mg/kg treated group (MLEL), and loperamide and LAB-fermented MLE 600 mg/kg treated group (MLEH). After 33 d, fecal pellet amount, fecal weight, water content of fecal, gastrointestinal transit time and length, and serum lipid profiles were measured. Constipation was induced via subcutaneous injection of loperamide (2.0 mg/kg b.w., twice a day) for the final 5 d of the experiment. After loperamide administration, the LAB-fermented MLE groups showed a significantly increase in the fecal pellets number, wet weight, and water content in rats compared with the C group. Moreover, increases in the intestinal length and viable Lactobacillus numbers in the feces were observed in the LAB-fermented MLE groups. The intestinal transit time was shorter in the LAB-fermented MLE groups than in the C group. In addition, the LAB-fermented MLE groups showed a significant decrease in triglyceride and total cholesterol levels and an increase in HDL-cholesterol level. These results indicated that oral administration of LAB-fermented MLE shows laxative effect in loperamide-induced constipated rats.

We developed a graphene nanoplatelet-modified fluorine-doped tin oxide electrode (GNP/FTO) for the simultaneous detection of dopamine (DA) and uric acid (UA) in the presence of ascorbic acid (AA) and investigated the interaction mechanisms of DA, UA, and AA with GNPs considering their charging states at different pH values. Owing to the unique structure and properties originating from the oxygen and nitrogen functional groups at the edges, GNPs showed high electrocatalytic activity for the electrochemical oxidations of AA, DA, and UA with peak-to-peak potential separations (ΔEP) between AA-DA and DA-UA of ca. 0.23 and 0.17 V, respectively. These values are sufficiently high to allow the simultaneous detection of DA and UA without interference from AA. The highly sensitive and stable GNP/FTO sensor showed sensitivities of ca. 0.15 ± 0.004 and 0.14 ± 0.007 μA/μM, respectively, with detection limits of ca. 0.22 ± 0.009 and 0.28 ± 0.009 μM, respectively, for DA and UA. The sensor could detect DA and UA concentrations in human serum samples with excellent recoveries.

Obesity has recently risen and become a serious health concern in Korea according to the westernized diet and altered lifestyle. Hence, there is a growing interest in the supplementation of phytochemicals to find a safe and effective functional ingredient to treat obesity. Spergularia marina Griseb (SM) has traditionally been used as a natural herb against chronic diseases in Korea. In this study, we investigated the antiobesity effects of SM in vitro and in vivo. SM ethanol extract (SME) inhibited proliferation and differentiation in murine adipocytes and primary porcine pre-adipocytes in a dose-dependent manner. In the in vivo study, supplementation of SM powder (SMP) remarkably attenuated fat accumulation in HFD-induced obese rats. In addition, SMP supplementation improved lipid profiles in the serum and tissues of high-fat induced obese rats. Collectively, these data indicated that SME exhibited antiobesity effects by modulating adipogenesis and lipolysis. Furthermore, SMP could be developed as an obesity-induced metabolic syndrome treatment.

Nanostructured copper-cobalt oxide (CuxCo3-xO4, CCO) electrodes are grown directly on conducting substrates via electrochemical deposition; then, various factors (e.g., oxygen vacancies, electrochemically active surface area, and electrical conductivity) affecting their electrocatalytic activity for oxygen evolution reactions (OERs) are studied. The observed OER performance decreases when increasing the annealing temperature due to the nanostructure deformation and agglomeration and the decreased number of oxygen vacancies, electrochemically active surface area, and electrical conductivity. An optimized nanopetal structure of CuxCo3-xO4 (x = 0.95, annealed at 200 °C) shows a considerably high Faradaic efficiency (∼93%) with a remarkably low overpotential (∼230 mV) at a benchmark current density (J) of 10 mA cm-2; at the same J in an alkaline solution (1 M KOH) for OER, it also exhibits high durability (up to 100 h). This study provides a complete guide for designing efficient and robust spinel-type CCO electrocatalysts through a facile electrochemical route. - Qatar National Research Fund (QNRF) - grant #NPRP 10 1210 160019. - National Research Foundations - grant #2019M1A2A2065616, 2019R1A2C2002602. - Ministry of Science, ICT and Future Planning (MSIP)- grant #NRF-2015M1A2A2054996, NRF-2016M1A2A2940912.

Gaining deep insight into the operative mechanism of organic photovoltaic (OPV) devices made of perylene-diimide (PDI) electron acceptors is challenging. Herein we perform a comparative study of three different solution-processable PDI-based heterojunctions for identifying the parameters limiting their OPV device performance. In all three systems the PTB7-Th polymer serves as the electron donor mixed with one of the three derivatives of the EP-PDI monomer, and the C6-PDI2 and BG-PDI2 dimers. The obtained power conversion efficiency (PCE) of these PTB7-Th:PDI systems is PCEEP-PDI = 3.65%, PCEC6-PDI2 = 5.36%, and PCEBG-PDI2 = 4.12%. Despite the existing major differences in the molecular structure of the PDI acceptors the electron transport properties of all three PTB7-Th:PDI layers remain in the same order of ∼10−6 cm2 V−1 s−1. The electron mobility is found to have an activation energy close to ∼10kT thereby reflecting a high content of physical disorder in the three PDI acceptors. The endemic characteristic of trap-limited charge transport in PDI-based OPV layers is verified by (i) the dependence of open-circuit voltage on light intensity and (ii) the transient photovoltage characterization of the PTB7-Th:PDI devices. Based on GIWAXS measurements, the size of the well-ordered electron transporting domains in the OPV layers is between 4.0 and 6.8 nm, yet no evidence for PDI nanograin morphology features of the PDI multiadducts is found by scanning electron microscopy imaging. Photoluminescence spectroscopy reveals that all three PDI derivatives form emissive excimer-like states in the solid state, albeit with a different excimer stabilization energy. The losses induced by charge trapping are found to be increased in PTB7-Th:BG-PDI2, that is the derivative exhibiting the most stabilized excimer state and the smallest domain size. The optimum device efficiency of the C6-PDI2 heterojunction is attributed to its capability to form medium-sized electron transporting domains that are less disconnected by traps of disordered C6-PDI2 dimers. These findings signify the importance for PDI-dimer electron acceptors to maintain a three-dimensional configuration when used in OPV layers.

Two NIR BODIPY dyes T′2P2A and T′′2P2A were synthesized and used as photosensitizers in dye sensitized solar cells (DSSCs). T′2P2A and T′′2P2A were designed by incorporation of bis-thienyl vinyl and thienothiophene vinyl side-arms in the structure. This leads to a red shift in the absorption spectra leading to an enhancement in the incident photon to current conversion efficiency (IPCE). A high IPCE value of 64% at 750 nm and a power conversion efficiency (PCE) of 6.06% were observed for the T′2P2A based DSSC. Furthermore, based on the complementary absorption spectra of TP2A and T′2P2A, even more efficient co-sensitized DSSCs were fabricated. The DSSC based on TP2A + T′2P2A shows an enhancement in the IPCE from 47% to 74% at 550 nm compared to that based on the single dye system T′2P2A. Finally, a high PCE of 6.67% was obtained for the TP2A + T′2P2A co-sensitized DSSC, which was higher than the performances of each individual dye.

The aim of this study was to compare whether gochujang products prepared using giant embryo rice koji (rice gochujang, RG) and wheat koji (wheat gochujang, WG) have anti‐obesity effects on rats fed a high‐fat diet (HFD), who served as a model for obesity. The nutritional composition of RG and WG including proximate constituents, amino acid and fatty acid compositions were investigated. Consequently, the secondary fermented metabolites were analyzed in RG and WG by ultrahigh‐performance liquid chromatography and mass spectrometry. Rats were fed a HFD containing 10% RG powder (HFD‐RG) or 10% WG powder (HFD‐WG) for 8 weeks. Body weight gain, weights of liver, epididymal, retroperitoneal, perirenal, and total white fat pads, and levels of serum triglyceride (TG), total cholesterol, low‐density lipoprotein cholesterol, and leptin were lower in all gochujang groups than in the HFD group. Furthermore, RG and WG treatment decreased the hepatic TG content and lipid accumulation and significantly reduced the size of epididymal adipocytes. These effects are probably mediated through inhibition of hepatic fatty acid synthase, acetyl CoA carboxylase, malic enzyme, and adipose tissue lipoprotein lipase activities. The anti‐obesity effect was slightly greater in the HFD‐RG group than in the HFD‐WG group. This effect may be attributed to secondary metabolites, such as capsaicin, genistein, daidzein, soyasaponin, and lysophosphatidylcholines, contained in gochujang prepared using giant embryo rice or wheat koji., The aim of this study was to compare whether gochujang products prepared using giant embryo rice koji (RG) and wheat koji (WG) have anti‐obesity effects on rats fed a high‐fat diet (HFD). Anti‐obesity effects were slightly greater in the HFD‐RG group than in the HFD‐WG group. These effects were attributed to secondary metabolites, such as capsaicin, genistein, daidzein, soyasaponin and lysophosphatidylcholines, contained in gochujang prepared using giant embryo rice or wheat koji.

In this study, nickel hydroxide nanoparticles (NPs) decorated with nitrogen doped multiwalled carbon nanotubes (N-MWCNT) hybrid composite was synthesized by thermal reduction process in the presence of cetyl ammonium bromide (CTAB) and urea. The as-synthesized Ni(OH)2@N-MWCNT hybrid composite was characterized by FTIR, Raman, XRD, BET, BJH and FE-TEM analyses. These prepared porous carbon hybrid composite materials possessed high specific surface area and sheet like morphology useful for active electrode materials. The maximum specific capacitance of Ni(OH)2@N-MWCNT hybrid nanocomposite in the two electrode system showed 350 Fg−1 at 0.5 A/g,energy density ~43.75 Wkg−1 and corresponds to power density 1500 W kg−1 with excellent capacity retention after 5000 cycles. The results suggest that the prepared two-dimensional hybrid composite is a promising electrode material for electrochemical energy storage applications.

The aim of this study was to investigate the ability of Lactobacillus plantarum EM as a starter culture to control cabbage–apple juice fermentation and to explore the cholesterol‐lowering effects of the fermented juice (EM juice) in rats. L. plantarum EM produced strong antimicrobial activities against bacteria and fungi, suppressing other microorganisms in the fermented juice, and was the dominant organism during fermentation and storage. The EM juice also showed strong and broad‐spectrum antimicrobial activity. Rats fed a high‐fat and high‐cholesterol diet and administered EM juice showed significantly reduced total cholesterol (TC), triglyceride, and LDL‐cholesterol levels, as well as a reduced atherogenic index, lower cardiac factors in serum, and lower TC levels in the liver, while total lipid and TC levels in the rat feces increased. Reverse transcription–polymerase chain reaction analysis revealed that the hepatic mRNA expression of HMG‐CoA reductase decreased and the expressions of cholesterol 7α‐hydroxylase and low‐density lipoprotein receptor increased in rats administered EM juice. The effects of EM juice on rats included inhibition of cholesterol synthesis as well as enhancement of cholesterol uptake and cholesterol excretion. The results of this study indicate that the use of L. plantarum EM as a functional starter culture for juice fermentation exerts microbial control, enhances sanitary safety, and provides beneficial food effects against hypercholesterolemia.

Organic indoor photovoltaics (OIPVs) for the development of a wireless power supplier that allows the portable operation of Internet-of-things and low-energy consumption devices have received tremendous interest. Particularly, polythiophene represented by poly(3-hexylthiophene) has been considered as a promising photoactive material for OIPVs owing to their desirable optoelectrical properties and power conversion efficiencies (PCEs) that exceed Si-based PVs under low-intensity illumination. However, the polythiophene-based OIPVs suffer from an inadequate charge transporting ability in the out-of-plane direction and a low open-circuit voltage (VOC), which currently hinder the further improvement of OIPVs. Herein, we designed and synthesized a new polythiophene derivative by combining fluorination and random copolymerization strategies. The optimized polymer obtained by tuning the ratio of fluorinated and non-fluorinated bi-thiophene units showed an increased population of face-on oriented crystallites, a denser packing, and a deeper highest occupied molecule orbital energy level compared with its homopolymer analogue. The optimized polymer was also revealed to provide improved vertical charge transport than homopolymer analogue. As a result, when fabricated using the phenyl-C71-butyric acid methyl ester as an electron-acceptor, the OIPVs with the optimized polymer showed high PCEs up to 13.4% with VOC of 0.68 V under 1000 lux white light-emitting diode illumination, which were improved values compared with the efficiencies observed in the devices with homopolymer (PCE = 5.6% and VOC = 0.57 V).

Cellulose nanofiber (CNF) and hybrid zeolite imidazole framework (HZ) are an emerging biomaterial and a porous carbonous material, respectively. The composite of these two materials could have versatile physiochemical characteristics. A cellulose nanofiber and cobalt-containing zeolite framework-based composite was prepared using an in-situ and eco-friendly chemical method followed by pyrolysis. The composite was comprised of cobalt nanoparticles decorated on highly graphitized N-doped nanoporous carbons (NPC) wrapped with carbon nanotubes (CNTs) produced from the direct carbonization of HZ. By varying the ratio of CNF in the composite, we determined the optimal concentration and characterized the derived samples using sophisticated techniques. Scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS) confirmed the functionalization of CNF in the metallic cobalt-covered N-doped NPC wrapped with CNTs. The CNF–HZNPC composite electrodes show superior electrochemical performance, which is suitable for supercapacitor applications, its specific capacitance is 146 F/g at 1 A/g. Furthermore, the composite electrodes retain a cycling stability of about 90% over 2000 charge–discharge cycles at 10 A/g. The superior electrochemical properties of the cellulose make it a promising candidate for developing electrodes for energy storage applications.

In this article, we demonstrated the development of highly water-stable and conductive poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/graphene nanoplatelet (GNP) [PPG] composites on a fluorine-doped tin oxide (FTO) electrode for the detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) in aqueous medium. PPG was deposited on FTO via the electrospray technique from a mixture solution of PEDOT:PSS and GNPs, which was subsequently treated with sulfuric acid (H2SO4, 98%). Acid treatment enabled stabilisation of the GNPs on FTO in water, due to the removal of insulating and hydrophilic PSS (68%) from the composites, and concurrently increased the conductivity (105 S cm−1), owing to the presence of a high percentage of hydrophobic and conductive PEDOT, as well as strong π–π interactions between PEDOT and GNPs. The untreated PPG electrode exhibited low water stability of GNPs and low conductivity (23 S cm−1). Accordingly, the acid-treated PPG/FTO electrode showed very high electrochemical stability, low charge transfer resistance (Rct) at the electrode∣electrolyte interface, and improved catalytic activity for the oxidation of DA in aqueous buffer solution with very high sensitivity. It showed sufficiently high anodic peak-to-peak potential separations (ΔEpa) between DA and AA (0.27 V) and DA and UA (0.11 V) for the interference-free detection of DA with a detection limit (S/N = 3) and sensitivity of ∼105 nM and 27.7 μA μM−1 cm−2, respectively.