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Owing to the advantages of high theoretical capacity, low cost, and excellent chemical stability, Ni(OH) 2 is considered as a potential candidate for electrode materials of supercapacitors. However, its further applications are limited by its adverse surface chemical properties. In this paper, a composite material consisting of ZIF-67 derived Co-C-N nanosheets and Ni(OH) 2 was synthesized facilely on carbon cloth in situ , and based on the collective advantages of the various components, excellent electrochemical performance could be achieved when used as a flexible electrode material of supercapacitors. In detail, the as-obtained sample Ni(OH) 2 /Co-C-N/CC exhibits an ultrahigh specific capacitance of 2100 F g -1 at a current density of 1 A g -1 . Moreover, the further assembled asymmetric supercapacitor device exhibits a maximum energy density of 78.6 W h kg -1 at a power density of 749.4 W kg -1 . Furthermore, the device also shows outstanding cycling stability with 90.2% capacitance retention after 5000 cycles of charge-discharge. Basically, the remarkable performance can be attributed to the well-developed structure, abundant active sites, complex beneficial components, and their intrinsic properties. Significantly, rational design can broaden the research directions of corresponding electrode materials., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Photocatalytic water splitting is considered to be a feasible method to replace traditional energy. However, most of the catalysts have unsatisfactory performance. In this work, we used a hydrothermal process to grow Ag nanoparticles in situ on g-C 3 N 4 nanosheets, and then a high performance catalyst (Ag-g-C 3 N 4 ) under visible light was obtained. The Ag nanoparticles obtained by this process are amorphous and exhibit excellent catalytic activity. At the same time, the local plasmon resonance effect of Ag can effectively enhance the absorption intensity of visible light by the catalyst. The hydrogen production rate promote to 1035 μ mol g -1 h -1 after loaded 0.6 wt% of Ag under the visible light, which was 313 times higher than that of pure g-C 3 N 4 (3.3 μ mol g -1 h -1 ). This hydrogen production rate is higher than most previously reported catalysts which loaded with Ag or Pt. The excellent activity of Ag-g-C 3 N 4 is benefited from the Ag nanoparticles and special interaction in each other. Through various analysis and characterization methods, it is shown that the synergy between Ag and g-C 3 N 4 can effectively promote the separation of carriers and the transfer of electrons. Our work proves that Ag-g-C 3 N 4 is a promising catalyst to make full use of solar energy., (© 2022 IOP Publishing Ltd.)

As an important organic chemical raw material, methanol is used in various industries but is harmful to human health. Developing an effective and accurate detection device for methanol is an urgent need. Herein, we demonstrate a novel gas-sensing material with a Pt single atom supported on a porous Ag-LaFeO 3 @ZnO core-shell sphere (Ag-LaFeO 3 @ZnO-Pt) with a high specific surface area (192.08 m 2 ·g -1 ). Based on this, the surface activity of the Ag-LaFeO 3 @ZnO-Pt gas sensor is enhanced obviously, which improved the working temperature and detection limit for methanol gas. Consequently, this sensor possesses an ultrahigh sensitivity of 453.02 for 5 ppm methanol gas at a working temperature of 86 °C and maintains a high sensitivity of 21.25 even at a concentration as low as 62 ppb. The sensitivity of Ag-LaFeO 3 @ZnO-Pt to methanol gas is increased by 6.69 times compared with the Ag-LaFeO 3 @ZnO core-shell sphere (Ag-LaFeO 3 @ZnO). Additionally, the minimum detection limit is found to be 3.27 ppb. Detailed theoretical calculations revealed that the unoccupied 5d state of Pt single atoms increases the adsorption and activation energy of methanol and oxygen, which facilities methanol gas-sensing performance. This work will provide a novel strategy to design high-performance gas-sensing materials.

Single-atom catalysts anchoring offers a desirable pathway for efficiency maximization and cost-saving for photocatalytic hydrogen evolution. However, the single-atoms loading amount is always within 0.5% in most of the reported due to the agglomeration at higher loading concentrations. In this work, the highly dispersed and large loading amount (>1 wt%) of copper single-atoms were achieved on TiO 2 , exhibiting the H 2 evolution rate of 101.7 mmol g -1  h -1 under simulated solar light irradiation, which is higher than other photocatalysts reported, in addition to the excellent stability as proved after storing 380 days. More importantly, it exhibits an apparent quantum efficiency of 56% at 365 nm, a significant breakthrough in this field. The highly dispersed and large amount of Cu single-atoms incorporation on TiO 2 enables the efficient electron transfer via Cu 2+ -Cu + process. The present approach paves the way to design advanced materials for remarkable photocatalytic activity and durability., (© 2022. The Author(s).)

Formaldehyde is a common carcinogen in daily life and harmful to health. The detection of formaldehyde by a metal oxide semiconductor gas sensor is an important research direction. In this work, cobalt-doped SnO 2 nanoparticles (Co-SnO 2 NPs) with typical zero-dimensional structure were synthesized by a simple hydrothermal method. At the optimal temperature, the selectivity and response of 0.5% Co-doped SnO 2 to formaldehyde are excellent (for 30 ppm formaldehyde, R a / R g = 163 437). Furthermore, the actual minimum detectable concentration of 0.5%Co-SnO 2 NPs is as low as 40 ppb, which exceeds the requirements for formaldehyde detection in the World Health Organization (WHO) guidelines. The significant improvement of 0.5%Co-SnO 2 NPs gas performance can be attributed to the following aspects: firstly, cobalt doping effectively improves the resistance of SnO 2 NPs in the air; moreover, doping creates more defects and oxygen vacancies, which is conducive to the adsorption and desorption of gases. In addition, the crystal size of SnO 2 NPs is vastly small and has unique physical and chemical properties of zero-dimensional materials. At the same time, compared with other gases tested, formaldehyde has a strong reducibility, so that it can be selectively detected at a lower temperature., Competing Interests: The authors declare no conflict of interest., (This journal is © The Royal Society of Chemistry.)

L-Histidine (L-His) is an essential amino acid, which is used to synthesize proteins and enzymes. The concentration of L-His in the body is controlled to regulate tissue growth and repair of tissues. In this study, a rapid and sensitive method was developed for colorimetric L-his detection using Cu 2+ ions to inhibit the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB)-H 2 O 2 system. H 2 O 2 can oxidize TMB to oxTMB in the presence of copper, and the change in color from colorless (TMB) to blue (oxTMB) is similar to that observed in the presence of peroxidase. However, because the imidazole ring and carboxyl group of L-His can coordinate with Cu 2+ ions to form stable L-His-Cu 2+ complexes, the color of the TMB-H 2 O 2 solution remains unchanged after the addition of L-His. Therefore, because L-His effectively hinders the colorimetric reaction of TMB with H 2 O 2 , this assay can be used to quantitatively determine the concentration of L-His in samples. Under optimized conditions, our colorimetric sensor exhibited two linear ranges of 60 nM to 1 μM and 1 μM to 1 mM for L-His detection and a detection limit of 50 nM (S/N = 3); furthermore, the assay can be performed within 20 min. Moreover, the proposed assay was used to determine the concentration of L-His in urine samples, suggesting that this convenient and label-free colorimetric method presents promising applications in bioanalytical chemistry and clinical diagnosis., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Zhang, Zhao, Hu, Cao, Liu and Liu.)

Background: This study aimed to investigate the expression characteristics of ANGPTL8 in patients with primary nephrotic syndrome and its possible correlation with hyperlipidemia and proteinuria., Methods: ANGPTL8 levels were determined using an enzyme-linked immunosorbent assay in 133 subjects with PNS and 60 healthy controls., Results: Compared with healthy controls, subjects with primary nephrotic syndrome had higher levels of serum and urine ANGPTL8 (P < 0.001). In primary nephrotic syndrome patients, serum ANGPTL8 was positively correlated with cholesterol (r = 0.209, P < 0.05) and triglycerides (r = 0.412, P < 0.001), while there was no correlation with 24 hUTP. Urine ANGPTL8 was positively correlated with high-density lipoprotein cholesterol (r = 0.181, P < 0.05) and was significantly negatively correlated with creatinine (r = - 0.323, P < 0.001), eGFR (r = - 0, P < 0.001) and 24 hUTP (r = - 0.268, P = 0.002). Interestingly, the urine ANGPTL8 concentrations in membranous nephropathy and mesangial proliferative glomerulonephritis pathological types were different., Conclusions: Serum and urine ANGPTL8 levels in primary nephrotic syndrome patients were correlated with blood lipid levels and proteinuria, respectively, suggesting that ANGPTL8 may play a role in the development of primary nephrotic syndrome hyperlipidemia and proteinuria.

Due to highly enzymatic d-stereoselectivity, l-nucleotides (l-2'-deoxynucleoside 5'-triphosphates [l-dNTPs]) are not natural targets of polymerases. In this study, we synthesized series of l-thymidine (l-T)-modified DNA strands and evaluated the processivity of nucleotide incorporation for transcription by T7 RNA polymerase (RNAP) with an l-T-containing template. When single l-T was introduced into the transcribed region, transcription proceeded to afford the full-length transcript with different efficiencies. However, introduction of l-T into the non-transcribed region did not exhibit a noticeable change in the transcription efficiency. Surprisingly, when two consecutive or internal l-Ts were introduced into the transcribed region, no transcripts were detected. Compared to natural template, significant lags in NTP incorporation into the template T+4/N and T+7/N (where the number corresponds to the site of l-T position, and + means downstream of the transcribed region) were detected by kinetic analysis. Furthermore, affinity of template T+4/N was almost the same with T/N, whereas affinity of T+7/N was apparently increased. Furthermore, no mismatch opposite to l-T in the template was detected in transcription reactions via gel fidelity analysis. These results demonstrate the effects of chiral l-T in DNA on the efficiency and fidelity of RNA transcription mediated by T7 RNAP, which provides important knowledge about how mirror-image thymidine perturbs the flow of genetic information during RNA transcription and development of diseases caused by gene mutation., (Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.)

To address the urgent issues of hazardous gas detection and the prevention of environmental pollution, various functional materials for gas sensing and catalytic reduction have been studied. Specifically, the p-type perovskite LaFeO 3 has been studied widely because of its promising physicochemical properties. However, there remains several problems to develop a controllable synthesis of LaFeO 3 -based p-n heterojunctions. In this work, α-Fe 2 O 3 was further compounded with LaFeO 3 to form a porous and hollow α-Fe 2 O 3 /LaFeO 3 heterojunction to improve its gas-sensing performance and photocatalytic efficiency via a microwave-assisted hydrothermal method. While evaluated as sensors of acetone gas, the optimized sample exhibits excellent performance, including a high response (48.3), excellent selectivity, good reversibility, fast response, and recovery ability. Furthermore, it is an efficient catalyst for the degradation of methylene blue. This can be attributed to the enhancement effect of its larger specific surface area, fast diffusion, enhanced surface activities, and p-n heterojunction. Additionally, this work provides a rapid and rational synthesis strategy to produce metal oxides with both enhanced gas-sensing performance and improved photocatalytic properties.

Xylene is a volatile organic compound which is harmful to the human health and requires precise detection. The detection of xylene by an oxide semiconductor gas sensor is an important research direction. In this work, Co 3 O 4 decorated flower-like SnO 2 nanorods (SnO 2 /Co 3 O 4 NRs) were synthesized by a simple and effective two-step method. The SnO 2 /Co 3 O 4 NRs show high xylene response (R g /R a  = 47.8 for 100 ppm) and selectivity at the operating temperature of 280 °C, and exhibit high stability in continuous testing. The resulting SnO 2 /Co 3 O 4 NRs nanocomposites show superior sensing performance towards xylene in comparison with pure SnO 2 nanorods. The remarkable enhancement in the gas-sensing properties of SnO 2 /Co 3 O 4 NRs are attributed to larger specific surface area and the formation of p-n heterojunction between Co 3 O 4 and SnO 2 . These results demonstrate that particular nanostructures and synergistic effect of SnO 2 and Co 3 O 4 enable gas sensors to selectively detect xylene.

Formaldehyde (HCHO) is the main source of indoor air pollutant. HCHO sensors are therefore of paramount importance for timely detection in daily life. However, existing sensors do not meet the stringent performance targets, while deactivation due to sensing detection at room temperature, for example, at extremely low concentration of formaldehyde (especially lower than 0.08 ppm), is a widely unsolved problem. Herein, we present the Ag nanoparticles (Ag NPs) sensitized dispersed In 2 O 3 nanograin via a low-fabrication-cost hydrothermal strategy, where the Ag NPs reduces the apparent activation energy for HCHO transporting into and out of the In 2 O 3 nanoparticles, while low concentrations detection at low working temperature is realized. The pristine In 2 O 3 exhibits a sluggish response (R a /R g = 4.14 to 10 ppm) with incomplete recovery to HCHO gas. After Ag functionalization, the 5%Ag-In 2 O 3 sensor shows a dramatically enhanced response (135) with a short response time (102 s) and recovery time (157 s) to 1 ppm HCHO gas at 30 °C, which benefits from the Ag NPs that electronically and chemically sensitize the crystal In 2 O 3 nanograin, greatly enhancing the selectivity and sensitivity.

In this work, we synthesized Sm 2 O 3 /ZnO/SmFeO 3 microspheres by a hydrothermal method combined with microwave assistance to serve as a methanol gas sensor. We investigated the effect on the microstructure at different hydrothermal times (12 h, 18 h, 24 h, and 30 h), and the BET and XPS results revealed that the specific surface area and adsorbed oxygen species were consistent with a microstructure that significantly influences the sensing performance. The gas properties of the Sm 2 O 3 -doped ZnO/SmFeO 3 microspheres were also investigated. With a hydrothermal time of 24 h, the gas sensor exhibited excellent sensing performance for methanol gas. For 5 ppm of methanol gas at 195 °C, the response reached 119.8 with excellent repeatability and long-term stability in a 30-day test in a relatively high humidity atmosphere (55-75% RH). Even at 1 ppm of methanol gas, the response was also higher than 20. Thus, the Sm 2 O 3 -doped ZnO/SmFeO 3 microspheres can be considered as prospective materials for methanol gas sensors.

Silver-doped LaFeO 3 molecularly imprinted polymers (SLMIPs) were synthesized by a sol-gel method combined with molecularly imprinted technology as precursors. The precursors were then used to prepare SLMIPs cage (SLM-cage) and SLMIPs core-shell (SLM-core-shell) structures by using a carbon sphere as the template and hydrothermal synthesis, respectively. The structures, morphologies, and surface areas of these materials were determined, as well as their gas-sensing properties and related mechanisms. The SLM-cage and SLM-core-shell samples exhibited good responses to methanol gas, with excellent selectivity. The response and optimum working temperature were 16.98 °C and 215 °C, 33.7 °C and 195 °C, respectively, with corresponding response and recovery times of 45 and 50 s (SLM-cage) and 42 and 57 s (SLM-core-shell) for 5 ppm methanol gas. Notably, the SLM-cage and SLM-core-shell samples exhibited lower responses (≤5 and ≤7, respectively) to other gases, including ethanol, ammonia, benzene, acetone, and toluene. Thus, these materials show potential as practical methanol detectors.

Ag-LaFeO 3 molecularly imprinted polymers (ALMIPs) were fabricated, which provided special recognition sites to methanol. Then ALMIPs fiber 1, fiber 2 and fiber 3 were prepared using filter paper, silk and carbon fibers template, respectively. Based on the observation of X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), and Nitrogen adsorption surface area analyzer (BET), the structure, morphology and surface area of the fibers were characterized. The ALMIPs fibers (fiber 1, fiber 2 and fiber 3) show excellent selectivity and good response to methanol. The responses to 5 ppm methanol and the optimal operating temperature of ALMIPs fibers are 23.5 and 175 °C (fiber 1), 19.67 and 125 °C (fiber 2), 17.59 and 125 °C (fiber 3), and a lower response (≤10, 3, 2) to other test gases including formaldehyde, acetone, ethanol, ammonia, gasoline and benzene was measured, respectively.

Metal oxide semiconductors with special structures and morphologies have attracted considerable attention because of their promising applications in gas sensors. In this paper, Ag-LaFeO 3 fibers, spheres and cages have been prepared. Based on X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), Brunauer-Emmett-Teller (BET) nitrogen adsorption and transmission electron microscopy (TEM) observations, the structure and morphology of the products were characterized. It has been revealed that the as-prepared materials have uniform morphologies and consist of numerous nanocrystals. Sensors based on the Ag-LaFeO 3 fibers, spheres and cages all exhibited high responses and good selectivities to formaldehyde gas. Owing to their hollow and porous structure, large surface area and greater number of surface active sites, the Ag-LaFeO 3 cages have the lowest operating temperature. The results suggest that the as-prepared Ag-LaFeO 3 fibers, spheres and cages, especially the cages, are promising candidates for high performance formaldehyde sensors.