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In this study, a highly efficient peroxymonosulfate (PMS) activator, ZnO/ZnMn2O4, was synthesized using a simple one‐step hydrothermal method. The resulting bimetallic oxide catalyst demonstrated a homogenous and high‐purity composition, showcasing synergistic catalytic activity in activating PMS for degrading 2, 4‐dichlorophenol (2, 4‐DCP) in aqueous solution. This catalytic performance surpassed that of individual ZnO, Mn2O3, and ZnMn2O4 metal materials. Under the optimized conditions, the removal efficiency of 2, 4‐DCP reached approximately 86% within 60 min, and the catalytic ability remained almost constant even after four cycles of recycling. The developed degradation system proved effective in degrading other azo‐dye pollutants. Certain inorganic anions such as HPO4−, HCO3−, and NO3− significantly inhibited the degradation of 2, 4‐DCP, while Cl− and SO42− did not exhibit such interference. Results from electrochemical experiments indicated that the electron transfer ability of ZnO/ZnMn2O4 surpassed that of individual metals, and electron transfer occurred between ZnO/ZnMn2O4 and the oxidant. The primary active radicals responsible for degrading 2, 4‐DCP were identified as SO4•−, OH• and O2•−, generated through the oxidation and reduction of PMS catalyzed by Zn (II) and Mn (III). Furthermore, X‐ray photoelectron spectroscopy (XPS) analysis of the fresh and used catalysts revealed that the exceptional electron transfer ability of ZnO facilitated the valence transfer of Mn (III) and the transfer of electrons to the catalyst's oxygen surface, thus enhancing the catalytic efficiency. The analysis of radicals and intermediates indicates that the two main pathways for degrading 2, 4‐DCP involve hydroxylation and radical attack on its aromatic ring. Practitioner Points: A bimetallic ZnO/ZnMn2O4 catalyst was synthesized and characterized.ZnO/ZnMn2O4 can synergistically activate PMS to degrade 2, 4‐DCP compared with single metal oxide.Three primary active radicals, O2•−, •OH, and SO4•−, were generated to promote the degradation.ZnO promoted electron transfer among the three species of Mn to facilitate oxidizing pollutants.Hydroxylation and radical attack on the aromatic ring of 2, 4‐DCP are the two degradation pathways. [ABSTRACT FROM AUTHOR]

In this work, a reusable DNA sensing microchip was developed for detection of vomitoxin (deoxynivalenol, DON) in sorghum using Cd-based core-shell CdSe@CdS quantum dots (QDs) as promising electrochemiluminescence (ECL) emitter. The size-adjustable aqueous phase CdSe@CdS QDs were prepared through homogeneous method, exhibiting strong cathodic ECL emission with a central wavelength of 520 nm in S 2 O 8 2− coreactant. And gold nanoparticles-modified iron cobalt cyanide hydrate (Fe–Co–Au) was introduced as an accelerator to amplify the ECL signal. ECL signal was quenched after the formation of a double-stranded (dsDNA) S1–S2 by generating an electron transfer system between the emitter and ferrocene (Fc), which are modified on the aptamer (ssDNA S1) and its complement sequence (ssDNA S2), respectively. When the target DON is presence, the aptamer ssDNA S1 will bind to the DON and trigger the unbinding of double strands DNA and the release of the ssDNA S2, thus the signal can be generated. This approach offers a feasible method for the detection of DON within the range of 1 ng/mL to 200 ng/mL. [Display omitted] • The detection processes are performed in the reusable microchip. • CdSe@CdS QDs as ECL emitter showed remarkable potential in vomitoxin sensor. • The ECL enhancement mechanism of Fe–Co–Au accelerator was fully discussed. • The hybridization chain reaction was introduced into the sensing system. [ABSTRACT FROM AUTHOR]

Synopsis: Lignin porous carbon/PANI composites were prepared via in- situ polymerization using lignin as carbon precursor. The PANI nanofibers interpenetrate the lamellar structure of lignin porous carbon, which endows high accessibility to ions and fast transfer for electrons, leading to the superior capacitance for the composite and the high energy density when assembled into supercapacitor. [Display omitted] Lignin porous carbons show good potential as carbon electrode materials for supercapacitors, but face the problem of low capacitance. Combining lignin porous carbons with polyaniline can achieve high capacitance. However, capacitance degradation resulting from the poor compatibility between lignin porous carbons and polyaniline has been the major obstacle for their application. In this work, three lignin porous carbons with different geometries were used as the hosts to anchor polyaniline for carbon/polyaniline composites via in- situ oxidative polymerization, and the compatibility between lignin porous carbons and polyaniline was investigated. It was determined the lamellar hierarchical lignin porous carbon with crumpled nanosheets can provide a large accessible surface area for the heterogeneous nucleation of aniline, which ensures uniform loading of interpenetrating polyaniline nanofibers. Benefiting from the interpenetrating conductive network and enhanced compatibility, the lamellar hierarchical porous carbon/polyaniline composite possesses a high capacitance of up to 643 F/g at 1.0 A/g and a sufficient capacitance of 390 F/g at 30.0 A/g. This work therefore provides design guidance for carbon hosts in high-performance supercapacitor composite electrodes. [ABSTRACT FROM AUTHOR]

• Methylophilus could use ferrihydrite as an electron acceptor. • Iron-dependent metabolism supports Methylophilus to survive in oxygen-limited condition. • Cytochrome c and riboflavin are involved in extracellular electron transfer of Methylophilus. Methylophilus methylotrophs, as representatives of C1 microbes, widely exist in the interface of hyperoxia–hypoxia environment and plays a key role in global carbon cycle. Most studies of Methylophilus were carried out under hyperoxic conditions, while it remains unclear how Methylophilus survive under oxygen-limited conditions. In this study, we report that ferrihydrite could serve as an alternative electron acceptor for Methylophilus strain with reduction rate of 53.6 μM Fe(II) d−1, when cells were deprived of oxygen. Genomic analysis and electrochemical measurements suggested that two strategies, cytochrome c and riboflavin, were involved in the extracellular mineral respiration. Respiration of extracellular electron acceptor by a Methylophilus strain demonstrated in this study broadens our understanding of energy metabolism by Methylophilus and suggests as a survival strategy for these microbes under oxygen-limited conditions. The results also demonstrate Methylophilus spp. as novel type of electrochemical active microbes that could be applied in bioelectrochemical systems with single-carbon substrate. [ABSTRACT FROM AUTHOR]

Microbial extracellular electron transfer (EET) plays a vital role in globally important environmental phenomena, including bioremediation, bioenergy generation, and biofuel production. The quantitation of microbial exoelectrogenic ability is fundamental to studying the process of EET. However, there is no accurate and time-saving protocol to directly evaluate EET ability, hindering our understanding and application of EET. In this work, we proposed an accurate and rapid quantitation system for measuring EET ability using a gold-coated membrane filter as a working electrode. The quantitation signals could be recorded within 1 h and accurately normalized by the number of cells with outstanding repeatability and reproducibility. Further, this method could be distinguished microbial direct EET performances of different growth stages, and the results showed the middle logarithmic growth stage of Shewanella onedensis MR-1 had the best electrochemical activity. This method can be widely used for different types of electroactive microorganisms, including gram-negative bacteria, gram-positive bacteria, and fungi. Due to its time savings, accurate quantification and easy operation, this method provides a standard way to assess the role of EET ability. • RQEET combined the features of filtration and conductivity to obtain a new type of electrode. • RQEET can quantify microbial EET ability in a short time (≤1 h). • RQEET shows great repeatability by controlling the number and growth stage of loading cells. • RQEET is flexible to integrate into biological techniques for molecular studies. [ABSTRACT FROM AUTHOR]

Abstract: Electroreduction behavior of three dibromobenzenes (1) has been investigated by cyclic voltammetry on glassy carbon and silver electrodes in DMF in the absence and presence of CO2. For meta- and para-dibromobenzenes, two successive two-electron reduction peaks could be detected, attributed to sequential cleavage of two reductive C–Br bond, while most of ortho-dibromobenzene underwent four-electron transfer reduction simultaneously. Related to distinguished electroreduction behaviors of three dibromobenzenes, distinct carboxylation rules were indicated. Both meta- and para-dibromobenzenes generally gave mono-carboxylation product of methyl bromobenzoate (3), while dehalogenated carboxylation product of methyl benzoate (2) was mainly obtained for the ortho-dibromobenzene. Moderate to good electrocarboxylation yields (49–74%) were obtained by preparative electrolyses in an undivided cell equipped with Mg rod as the sacrificial anode in the presence of CO2. Among the investigated electrode materials such as Ag, Cu, Ti and Ni, both cyclic voltammetry and confirmative electrolysis revealed the catalytic ability of Ag in the electroreduction and electrocarboxylation of dibromobenzenes. [Copyright &y& Elsevier]

The spectral and polarity dependence of the quantum yield of charge carrier photo-generation was studied by steady-state photocurrent measurement in a single layer PhPPV film, double layer film of PhPPV and R6G and doped film of PhPPV with R6G. The intrinsic and extrinsic charge carrier photogeneration was observed. The result indicates that the quantum efficiency of the double layer device is higher than that of single layer device under reverse bias, but it is opposite under forward bias. The yield of charge carrier photogeneration of the doped film is higher than that of the other two films at both forward and reverse bias because of the increased interface area between the electron donor and acceptor. [ABSTRACT FROM AUTHOR]

Carcinoembryonic antigen (CEA) is a significant glycosylated protein, and the unusual expression of CEA in human serum is used as a tumor marker in the clinical diagnosis of many cancers. Although scientists have reported many ways to detect CEA in recent years, such as electrochemistry, photoelectrochemistry, and fluorescence, their operation is complex and sensitivity is average. Therefore, finding a convenient method to accurately detect CEA is significance for the prevention of malignant tumors. With high sensitivity, quick reaction, and low background, electrochemiluminescence (ECL) has emerged as an essential method for the detection of tumor markers in blood. In this work, a "signal on-off" ECL immunosensor for sensitive analysis of CEA ground on the ternary extinction effects of CuFe 2 O 4 @PDA-MB towards a self-enhanced Ru(dcbpy) 3 2+ functionalized metal-organic layer [(Hf)MOL-Ru-PEI-Pd] was prepared. The high ECL efficiency of (Hf)MOL-Ru-PEI-Pd originated from the dual intramolecular self-catalysis, including intramolecular co-reaction between polyethylenimine (PEI) and Ru(dcbpy) 3 2+. At the same time, loading Pd NPs onto (Hf)MOL-Ru-PEI could not only improve the electron transfer ability of (Hf)MOL-Ru-PEI, but also provide more active sites for the reaction of Ru(dcbpy) 3 2+ and PEI. In the presence of CEA, CuFe 2 O 4 @PDA-MB-Ab 2 efficiently quenches the excited states of (Hf)MOL-Ru-PEI-Pd by PDA, Cu2+, and methylene blue (MB) via energy and electron transfer, leading to an ECL signal decrease. Under optimal conditions, the proposed CEA sensing strategy showed satisfactory properties ranging from 0.1 pg mL−1 to 100 ng mL−1 with a detection limit of 20 fg mL−1. The (Hf)MOL-Ru-PEI-Pd and CuFe 2 O 4 @PDA-MB were prepared in this work might open up innovative directions to synthesize luminescence-functionalized MOLs and effective quencher. Besides, the ECL quenching mechanism of Ru(dcbpy) 3 2+ by MB was successfully explained by the inner filter effect (ECL-IFE). At last, the proposed immunosensor exhibits excellent repeatability, stability, and selectivity, and may provide an attractive way for CEA and other disease markers determination. [Display omitted] • ECL signal originated from intramolecular co-reaction between PEI and Ru(dcbpy) 3 2+. • CuFe 2 O 4 @PDA-MB quenches the excited states of Ru(dcbpy) 3 2+ by PDA, Cu2+, and MB. • ECL signal quenching of Ru(dcbpy) 3 2+ by MB was explained by the inner filter effect. • High-performance ECL immunosensing of CEA. [ABSTRACT FROM AUTHOR]

A novel competitive ECL immunosensor for detection of 17β-Estradiol (E2) has been fabricated successfully. CdSe–ZnSe nanocomposites (CdSe–ZnSe NCs) with high catalytic properties, large surface area and good conductivity were used synergistically as the ECL nanocarriers of Pt nanoparticles (PtNPs). The ECL intensity of CdSe–ZnSe NCs increased and stabilized with luminol-PtNPs (luminol-PtNPs@CdSe–ZnSe NCs) because of electron transfer. To achieve the successful assembling of competitive ultrasensitive ECL immunosensor with high sensitivity and synergistic effect, Ag@TiO 2 core-shell was introduced as label. Ag@TiO 2 acted as a signal amplifier and also exhibited the high catalytic activity towards H 2 O 2. This firmly anchored the E2 Antigen with covalent bond and converted the longer wavelength radiations to shorter wavelength. Under optimized conditions, our proposed strategy quantify the selective and reliable analysis of E2 with detection limit of 2.51 fg/mL (S/N = 3) within the linear range of 0.0001–30 ng/mL. The assembled synergistic strategy-based ECL immunosensor manifested the promising sensitivity, selectability along with high level of repeatability. Thus, the fabricated ECL immunosensor has potential valuable application for E2 detection along with many other environmental pollutants. [Display omitted] • Luminol-PtNPs@CdSe–ZnSe NCs based competitive ECL immunosensor has been developed for 17β-estradiol (E2) detection. • Synergy of CdSe–ZnSe NCs and Ag@TiO 2 catalyze luminol–H 2 O 2 system to effectively amplify ECL signal. • The immunosensor exhibited a low detection limit of 2.51 fg/mL for E2. [ABSTRACT FROM AUTHOR]

[Display omitted] Under the context of energy shortages and global warming, the photocatalytic reduction of carbon dioxide (CO 2) to carbon monoxide (CO) using simulated sunlight has attracted considerable research attention. Herein, three-dimensional (3D) Z-scheme cobalt–alumina-layered double hydroxide/bismuth oxybromide (CoAl-layered double hydroxide (LDH)/BiOBr) heterojunction photocatalysts with oxygen vacancies were constructed by intercalating two-dimensional CoAl-LDH between BiOBr layers in the mechanical mixing. The conversion of CO 2 in the water phase was greatly improved compared to CoAl-LDH/BiOBr under 300-W xenon light. The transformation efficiency of 23.62 μmol⋅g−1⋅h−1 for CoAl-LDH/BiOBr-10 (CBO-10) is 2.96 and 8.34 times that of pure BiOBr and CoAl-LDH, respectively, with CO selectivity in the obtained products reaching as high as 95 %. Furthermore, CBO-10 catalysts exhibited outstanding stability in terms of structure and catalytic performance. The construction of Z-scheme heterojunctions and oxygen vacancies enlarges the photoresponse range of the BiOBr catalyst while reducing the photoelectron–hole recombination efficiency. The unique 3D structure offers more Z-scheme heterojunction interfaces for the separation and transfer of electrons between CoAl-LDH and BiOBr during photoreaction. This study is expected to guide the development of new high-performance photocatalysts and the selective regulation of reduction products. [ABSTRACT FROM AUTHOR]

In this study, a simple method was designed to prepare ordered mesoporous carbons embedded with molybdenum without any extreme conditions. We prepared three different ordered molybdenum carbide materials with mesoporous structures to explore the influence of the structure of molybdenum‐based materials on the HER catalytic efficiency. The ordered mesoporous molybdenum carbide catalysts (CMK‐3‐MoCx, fCMK‐3‐MoCx, CMK‐8‐MoCx) were characterized by SEM, TEM, XRD, nitrogen adsorption‐desorption and XPS. The HER is catalyzed efficiently on the three electrocatalysts, fCMK‐3‐MoCx shows the best HER electro‐catalytic performance with a small onset potential of −0.06 V vs. RHE, a low tafel slope of 66 mV dec−1 and a small over‐potential value of 89 mV at 10 mA cm−2. This excellent performance on HER is due to its high specific surface area and highly ordered mesoporous structure that resulted in excellent proton transport efficiency and high electron transfer rate. Our results provide a new research direction for the application of flat ordered mesoporous structures in catalysis. [ABSTRACT FROM AUTHOR]

Multipores engineering composed of micro/mesopores is an effective strategy to improve potassium storage performance via providing enormous adsorption sites and shortened ions diffusion distance. However, a detailed exploration of the role played by macropores in potassium storage is still lacking and has been barely reported until now. Herein, a superstructure carbon hexahedron (DGN‐900) is synthesized using poly tannic acid (PTA) as precursor. Due to the spatially confined two‐step local contraction of PTA along different directions and dimensions during pyrolysis, defective nanosheets with macropores are formed, while realizing a balance between defects content and graphitization degree by regulating temperature. The presence of macropores is conducive to accelerating electrolyte ions rapid infiltration within electrode, and its pore volume can accommodate electrode structure fluctuation upon cycling, while the most suitable ratio of defects to graphitic provides rich ions adsorption sites and sufficient electrons transfer channels, simultaneously. These advantages enable a prominent electrochemical performance in DGN‐900 electrode, including high rate (202.9 mAh g−1 at 2 A g−1) and long cycling stability over 2000 cycles. This unique fabrication strategy, that is, defects engineering coupled with macropores structure, makes fast and durable potassium storage possible. [ABSTRACT FROM AUTHOR]

High-efficiency and economical electrocatalysts for electrochemical water splitting are the core component of the renewable energy conversion. Herein, a simple and economical strategy is described to synthesize a series of metal oxide decorated nitrogen-doped carbon nanotubes materials (N-CNT@Cu–Fe Oxide Alloy NPs) by utilizing carbon nanotubes as the substrate carrier material. Additionally, the polypyrrole (PPy) was served as both the nitrogen resource and the localizing agent to load the Cu–Fe oxide alloy. Moreover, the theoretical and test results indicated that the superior HER and ORR performance is mainly related to the synergistic effect between the nitrogen-doped CNT and metallic oxide alloy. In the series of catalysts we prepared, N-CNT@Cu 1 –Fe 1 Oxide Alloy NPs exhibits more significant catalytic activity and better durability than other catalysts that we synthesized. Meanwhile, the catalyst shows the low Tafel slope of 68.28 mV dec−1 for HER and reaches 10 mA cm−2 at the overpotential of 375 mV. The K–L plot shows that the electron transfer number of N–CNF@Cu 1 –Fe 1 Alloy NPs is 3.43. [Display omitted] • Utilizing a new carbon nanotube as the substrate carrier material. • N-doping and oxide alloy formation can be simultaneously realized. • Polypyrrole as nitrogen source and localizing agent simultaneously. • Electron transfer between FePc and Cu2+ for the formation of metallic precursors. • High electrocatalytic performance for both HER and ORR. [ABSTRACT FROM AUTHOR]

Selective catalytic reduction of NO x with ammonia (NH 3 -SCR) under the exposure of multiple poisons in fly ash remains a great challenging issue for environmental protection. Herein, the intelligently self-tunable defense effects of Ce(SO 4) 2 additive modification for the V 2 O 5 /CeO 2 catalyst with excellent resistance against K and Zn co-poisoning was originally illustrated. The Ce(SO 4) 2 additive could firstly act as an inhibitor to certainly restrain the electron transfer between V and Ce species to decrease the redox property, but the high NO x reduction efficiency of Ce(SO 4) 2 modified fresh catalyst could be maintained due to the enhancement of vanadium species polymerization and acidity. Unexpectedly, the Ce(SO 4) 2 additive would smartly translate to act as a promoter over the co-poisoned catalyst to effectively combine with poisons, thus releasing most active vanadium species to exhibit superior co-poisoning resistance to K and Zn. This work provides a novel self-tunable multi-poisoning-resistant strategy via acid additive modification for SCR catalysts. [Display omitted] • Ce(SO 4) 2 modified vanadia catalyst was obtained to fight K and Zn co-poisoning. • Ce(SO 4) 2 modification greatly improved NO x conversion and co-poisoning resistance. • Ce(SO 4) 2 was inhibitor to restrain electron transfer between active V and Ce sites. • Ce(SO 4) 2 translates to promoter to fix K and Zn poisons among poisoned catalysts. [ABSTRACT FROM AUTHOR]

The improvement of electrochemiluminescence (ECL) performance relies on the electron transfer efficiency between luminophore and coreactant. An ultrasensitive ECL micro-reactor with confinement-enhanced performance was prepared by using the covalent organic framework-LZU1-functionalized metal-organic framework (MOF@COF-LZU1) as a platform to assemble enormous N,N -dibutyl-2-hydroxyethylamine (DBAE) and tris(4,4′-dicarboxylic acid-2,2′-bipyridyl) ruthenium(II) [Ru(dcbpy) 3 2+] into its pore channels. Compared to individual substances of γ-CD-MOF and COF-LZU1, the synergistic effects can conduce to the enhancement of the intensity, durability and sensitivity of the micro-reactor. Besides, COF-LZU1 can provide a mild environment to accommodate a certain amount of DBAE by concentrating them from the aqueous solution into its hydrophobic cavities and boost the oxidation efficiency of DBAE to generate more DBAE●+ and profited the survival of DBAE●, leading to an improved reaction efficiency with the Ru(dcbpy) 3 2+ intermediate. Thanks to the confinement-enhanced strategy, engineered as high-functioning luminescent materials, Ru@γ-CD-MOF@COF-LZU1 micro-reactors decorated with Au NPs can facilitate electron transfer and capture primary antibodies (Ab 1). Moreover, Au–Pd–Pt noble metal aerogels (NMAs) functionalized MoS 2 NFs (Au–Pd–Pt NMAs@MoS 2 NFs) were chosen as base material due to its large specific surface areas, high porosity, and excellent electrical conductivity. Based on above merits, the sensor demonstrated a sensitive response to CYFRA 21-1 detection in a linear concentration gradient from 10 fg/mL to 50 ng/mL with a detection limit of 0.0055 pg/mL (S/N = 3). The COF-LZU1 decorated ECL micro-reactors were constructed based on the signal amplification strategies to realize accurate CYFRA 21-1 detection. [Display omitted] • MOF@COF-LZU1 synergistic effects, the performance of ECL can be improved. • Ru@γ-CD-MOF@COF-LZU1 as high-functioning luminescent materials. • Au–Pd–Pt NMAs@MoS 2 NFs were chosen as base material. • The ECL immunosensor showed wide detection range and low LOD for CYFRA 21-1. [ABSTRACT FROM AUTHOR]

Lead ions (Pb2+) are heavy metal ions that are harmful to living organisms and ecosystems. It is important to realize sensitive detection of Pb2+ in the environment. In this study, a signal enhancement photoelectrochemical (PEC) sensor with high sensitivity was constructed for the detection of Pb2+. Firstly, to obtain excellent electron transfer performance, sulfur defect–engineered Bi 2 S 3–x /In 2 S 3–y mediated signal enhancement formed by Bi 2 S 3 and In 2 S 3 with well–matched structure in terms of energy level as the substrate materials. In this case, the introduction of sulfur vacancies further affects the electronic structure of the material, which significantly improves the electrical conductivity and effectively increases the electron transfer rate. In addition, the as–synthesized Cu@Cu 2 O nanosphere is chosen as the marker to accelerate the electron transfer through the surface plasmon resonance effect of Cu. The constructed sensor was able to detect Pb2+ in the range of 1 ng mL−1–100 μg mL−1 with a limit of detection of 19.2 pg mL−1. The sensor exhibits good reproducibility, specificity, and stability, indicating such PEC sensor can achieve the sensitive detection of Pb2+ in the environment. This work paves a new way for the construction of PEC sensors and the specific PEC detection of Pb2+ in environmental waters. [Display omitted] • Bi 2 S 3-x /In 2 S 3-y containing sulfur vacancies as substrate materials. • The introduction of sulfur vacancies promotes electron transfer. • Cu@Cu 2 O nanospheres as labeling and SPR effect of Cu to accelerate electron transfer. • Pb2+ breaks the phosphodiester bond in the aptamer. [ABSTRACT FROM AUTHOR]

A P/N co-doped three dimensional (3D) interconnected carbon nanocage was synthesized and highly stable electrochemical performance for potassium-ion batteries was realized. [Display omitted] Heteroatoms doping strategies are often considered to be an effective approach to provide rich active sites for capacitive-controlled potassium storage, and enlarged interspacing for intercalation process. However, the excess doping level will form a large number of sp3 defects and thus severely damage π-conjugated system, which is unfavorable for electron transfer. Herein, a P/N co-doped three-dimensional (3D) interconnected carbon nanocage (denoted as PN-CNC) is prepared with the help of a template-assisted method. The use of template and P heteroatom can contribute to forming a 3D interconnected carbon nanocage to prevent conductive carbon matrix from being excessively damaged, favoring a high electronic conductivity. The co-existence of P/N doping configurations with suitable content not only generate abundant defects, edge-voids, and micropores for significant capacitive behaviors, but also supply adequate interlayer space for intercalation process, and all these together ensure enhanced ion storage. As a result, the optimized PN-CNC electrode exhibits an exceptional reversible capacity (262 mAh g−1) and a superior rate capability (214.2 mAh g−1). Besides, long-term cycling stability is easily fulfilled by delivering a high capacity of 188.7 mAh g−1 at 2 A g−1 after 3000 cycles. [ABSTRACT FROM AUTHOR]

Rechargeable aqueous Zn//MnO 2 batteries are the promising alternatives to lithium-ion batteries owing to their high safety, high energy density, low cost, and environmental friendliness. However, the unstable MnO 2 cathode causes poor practical energy density and serious capacity fading. To overcome this issue, herein, a unique 2D nanosheets self-supported 3D δ -MnO 2 microflower hierarchical architecture is rationally designed and synthesized by taking advantage of its microwave-absorbing characteristics. The 2D nanosheets with high surface area could expose numerous active sites for ions/electrons transfer. Also, the 3D assembled structure acting as building blocks would ensure structural stability for long-life cycles. Benefiting from these synergistic merits, the δ -MnO 2 microflowers deliver a high capacity of 287.6 mA h g−1 at 0.5 C, an excellent rate capability of 202.7 mA h g−1 at 5 C, and a superior cycling retention of 76.5% over 1000 cycles at 10 C. Furthermore, a storage mechanism of H+/Zn2+ co-insertion accompanied by the deposition of zinc sulfate hydroxide hydrate is clarified by the aid of ex-situ XRD and SEM technologies. This work provides a new pathway for developing high capacity and long lifespan ZIBs. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Perovskite was used for asymmetric electrocarboxylation of aromatic ketones. • 85% yield and 95% enantiomeric excess were obtained on La 0.7 Sr 0.3 Fe 0.8 Ni 0.2 O 3. • The high-performance mainly results from the increased concentration of O2– and Fe4+. • La 0.7 Sr 0.3 Fe 0.8 Ni 0.2 O 3 has enhanced intrinsic electrochemical performance. The perovskite oxides La 0.7 Sr 0.3 Fe 0.8 B 0.2 O 3 (B = Ti, Mn, Co, Ni and Cu) synthesized by sol–gel method were used as cathodes and tested in asymmetric electrocarboxylation of aromatic ketones. The study showed the La 0.7 Sr 0.3 Fe 0.8 Ni 0.2 O 3 (La7Sr3Fe8Ni2) catalyst is more active for asymmetric electrocarboxylation of acetophenone with 95% enantiomeric excess and 85% yield. The high electrocatalytic activity is attributed mainly to several factors, including the increased amount of lattice oxygen and Fe4+ species on the surface of La7Sr3Fe8Ni2, enhanced electrochemically active surface area and faster electron transfer. Furthermore, La7Sr3Fe8Ni2 also exhibited remarkable stability and reusability. [ABSTRACT FROM AUTHOR]

• Ni–Co bimetallic nanoprisms anchored onto MPC supports were prepared by a simple method. • NiCo NR/MPC supports strongly enhanced electrocatalytic performance for glucose detection. • The novel NiCo NR/MPC hybrids will hold promise in development of electrode materials. In this study, a nickel–cobalt bimetallic nanorod-codoped macroporous carbon nanocomposite (NiCo NR/MPC) was prepared and used for glucose detection. NiCo NR was uniformly embedded into MPC scaffolds. The synergistic effect between the excellent electrocatalytic activity of NiCo NR and the remarkable conductivity of MPC carriers increased the electron transfer and the formation of numerous usable active sites. For glucose detection, the NiCo NR/MPC-glassy carbon electrode (GCE) exhibited a good linear range (0.1–831.7 μM) and a low limit of detection (0.063 μM) (S/ N = 3), with a high corresponding sensitivity of 206.8 μA mM−1 cm−2. Additionally, the GCE sensor was used to detect glucose under the same test conditions; the relative standard deviation (RSD) of the sensor was 4% after 10 repeated measurements. This indicated the reproducibility of the constructed NiCo NR/MPC-GCE sensor. Therefore, the constructed NiCo NR/MPC glucose electrochemical sensor has good application prospects. A Ni–Co bimetallic nanoprism loaded on macroporous carbon nanocomposite (NiCo NR/MPC) was prepared and used for detecting glucose. [Display omitted] [ABSTRACT FROM AUTHOR]

• Mo 2 C employed as nanocarriers of luminol-capped Au nanoparticles. • UCNPs-Pt@MOF used as label and signal amplification mediator. • The ECL immunosensor exhibited a low detection limit of 3.8 fg/mL. A competitive electrochemiluminescence (ECL) immunosensor for sensitive detection of diethylstilbestrol (DES) was successfully fabricated. Initially, molybdenum carbides (Mo 2 C) with excellent conductivity and large surface area were applied as the ECL reagent nanocarriers of luminol-capped Au nanoparticles (luminol-AuNPs). ECL performance of luminol-AuNPs with Mo 2 C (lumino-AuNPs@Mo 2 C) hybrid get enhanced in comparison with individual luminol-AuNPs due to facilitated electron transfer process. To carry out successful fabrication of competitive immunosensor, the label was constructed by encapsulating upconversion nanoparticles (UCNPs) functionalized by platinium into metal-organic frameworks (UCNPs-Pt@MOF). The synthesized UCNPs-Pt@MOF firmly anchored DES-antigen (Ag) by covalent bonding and was able to convert longer wavelength irradiation to shorter wavelength emission. In addition, UCNPs-Pt@MOF has been used as signal amplification mediator and it exhibited high catalytic activity towards hydrogen peroxide. Under optimal experimental condition, reliable and successful determination of DES was done within linear range of 0.1 pg/mL to 30 ng/mL with detection limit of 3.8 fg/mL (S/N = 3). The ECL immunosensor exhibited acceptable selectivity, good sensitivity and high repeatability. Moreover, the proposed competitive ECL immunosensor was evaluated by detecting DES in real water samples with satisfactory results. Therefore, this immunosensor has potential application values for detecting DES and other environmental pollutants. [ABSTRACT FROM AUTHOR]

• A novel Co and N co-doped mesoporous hollow carbon hemisphere was prepared by a simple method. • Co/N/HCHs nanocomposites displayed outstanding electrocatalytic performances for ORR. • The novel Co/N/HCHs will hold promise in development of high-efficient electrocatalysts. Exploring a cheap catalyst with effective activity for oxygen reduction reaction (ORR) to replace precious metal electrocatalysts has gained tremendous attention for several decades. In this study, we designed and synthesized cobalt and nitrogen supported on mesoporous hollow carbon hemisphere (Co/N/HCHs) nanocomposites by a facile and economical approach. Semisphere-shaped mesoporous hollow carbon is self-generated using silica particles as template, followed by a pyrolysis-etching process; and exhibits high electrical conductivity and high specific surface. The unique porous structure of carbon provides significant number of the abundant defective sites and shortens the mass transfer pathway, leading to a greatly enhanced electrocatalytic activity with mainly 4e- reduction. Moreover, the synergistic effects of large electrochemically active areas and good electrical conductivity, resulting from the introduction of Co and N heteroatom, are the main reason for displaying outstanding ORR activity with a high half-wave potential of 0.8 V and the electron transfer numbers of 3.89. Furthermore, an excellent long-term stability (the current density retention of 87.0%) and superb methanol tolerance in alkaline medium are achieved. Undoubtedly, this demonstrates a potential way to strategically design the non-precious metal doped carbon catalysts for wider practical applications. [ABSTRACT FROM AUTHOR]

• A sandwich-type signal off PEC sensor was constructed for PCT detection. • The photoactive matrix was Au NPs/BiOI NSs/B-TiO 2 NPs. • PbS/Co 3 O 4 was as a quenching signal label for signal amplification. • The PEC sensor exhibited a low detection limit of 0.02 pg/mL. A novel signal-off photoelectrochemical (PEC) immunosensor was proposed for procalcitonin (PCT) sensitive detection based on the Au nanoparticles/BiOI nanosheets/Black TiO 2 nanoparticles (Au NPs/BiOI NSs/B-TiO 2 NPs) as photoactive matrix and PbS quantum dots/Co 3 O 4 polyhedron (PbS/Co 3 O 4) as a quenching signal label for signal amplification. Concretely, BiOI NSs was fabricated by successive ionic layer absorption and reaction (SILAR) and formed the interlaced flake-like structure. Then Au NPs dropped on the BiOI NSs/B-TiO 2 NPs electrode forming Au NPs/BiOI NSs/B-TiO 2 NPs sensitization structure, which increased the utilization of visible light and accelerated electron transfer rate, resulting in a desirable PEC signal. PbS/Co 3 O 4 , an effective dual suppression signal quencher, was proposed for signal-off PEC immunosensor to weaken the photocurrent response because of the steric impedance, competitive absorption of light and competing consumption of electron donor. In this proposal, PCT was chosen to measure the performance of the suggested PEC immunosensor. Consequently, the fabricated PEC immunosensor showed a widely detection ranged from 0.1 pg/mL to 50 ng/mL and a low detection limit of 0.02 pg/mL (S/N = 3). What is more, the proposed PEC immunosensor possessed satisfactory selectivity, stability and reproducibility. [ABSTRACT FROM AUTHOR]

Organic-inorganic hybrid nano-material has a significant potential for enhancing the charge separation efficiency of photocatalyst. However, it remains an important issue to controllable synthesis new hybrid system with unique structure and earth-abundant materials for boosting photocatalytic hydrogen revolution. We report a facile one-step hydrothermal strategy to fabricate a novel Titania/β-cyclodextrin (TiO 2 /β-CD) organic-inorganic hybrid nano-material with an alveolate structure. In this hybrid system, β-CD not only played a critical role in alveolate structure formation, but also served as a bridge connecting target molecular and active sites on the TiO 2 surface to facilitate the separation and transfer of the photoexcited electrons with prolonged lifetime. As a result, this alveolate TiO 2 /β-CD composite exhibited outstanding photocatalytic activity and a H 2 evolution rate of 725 μmol/g·h was achieved over TiO 2 /β-CD which was 14 times of bare TiO 2 under simulated sunlight. This work paves a way for controllable synthesis of novel organic-inorganic hybrid nano-material with distinct structure for efficient photocatalysis. Image 1 • A novel alveolate organic-inorganic hybrid has been successfully prepared. • The hybrid composite exhibited outstanding photocatalytic activity. • The H 2 evolution rate of TiO 2 /β-CD has a good durability. • This work paves a way for controllable synthesis of organic-inorganic TiO 2. • Limited reports on the photocatalytic water splitting of the TiO 2 /β-CD. [ABSTRACT FROM AUTHOR]

Summary: Ni electrode was modified with graphene by the electrodeposition (ED) method to prepare an anode (anode‐ED) for microbial fuel cell (MFC). Electrochemical and morphological characterizations of anode‐ED along with the effects of anode modification on the MFC performance were investigated. The graphene modification based on cyclic voltammetric electrodeposition resulted in the decrease of charge transfer resistance (Rct) and improved extracellular electron transfer efficiency of anode. The maximum power density obtained from the MFC equipped with anode‐ED was 25.83 and 17.86 times larger than those of MFCs equipped with bare Ni anode and anode modified with graphene by traditional hydrothermal treatment method (anode‐HT), respectively. The electrochemical impedance spectroscopy (EIS) analysis results indicated that the Rct of anode decreased significantly after inoculation during the MFC operation. The improvement in power density was attributed to the decreasing Rct and the biocompatibility of graphene modified on anode‐ED surface. This study presented an effective electrodeposition method to make graphene‐modified anodes, which could improve the MFC performance. [ABSTRACT FROM AUTHOR]

Abstract A sandwich-type photoelectrochemical (PEC) immunosensing platform was designed for detection of amino-terminal pro-B-type natriuretic peptide (NT-pro BNP). Thereinto, flower-like Bi 2 WO 6 /Ag 2 S nanoparticles (F-Bi 2 WO 6 /Ag 2 S) were employed as photoelectrochemical matrix, and graphene oxide and polydopamine composite (GO/PDA) were prepared as signal labels. In this proposal, Ag 2 S was in-situ growth on the surface of F-Bi 2 WO 6 modified with thioglycolic acid (TGA). Specially, a cascade-like band-edge level between F-Bi 2 WO 6 and Ag 2 S effectively improved the photocurrent conversion efficiency and enhanced the photocurrent response. Then, the conjugated GO/PDA aimed to further amplify signal because PDA as electron donor could sweep the holes and inhibit the recombination of photogenerated electron-hole pairs, while GO owned brilliant conductivity speeding up the electrons transfer. The photocurrent increased with the amount of GO/PDA conjugates which had positive correlation with the NT-pro BNP. Under optimal experimental conditions, the proposed sandwich-type PEC immunosensor presented a desirable linear relationship ranged from 0.1 pg/mL to 100 ng/mL for NT-pro BNP with the detection limit of 0.03 pg/mL (S/N = 3). The prepared PEC immunosensor exhibited high stability and selectivity, which offered an innovative idea for the detection of other biomolecules. Highlights • A sandwich-type PEC immunosensor was fabricated for NT-pro BNP detection. • F-Bi 2 WO 6 loaded with Ag 2 S was used as photoactive matrix. • GO/PDA was first utilized as label for signal amplification. • The PEC immunosensor exhibited a low detection limit of 0.03 pg/mL. [ABSTRACT FROM AUTHOR]

Following hard template method, nitrogen–doped hollow carbon nanospheres (NHCPs) were successfully prepared by using monodisperse silica microspheres as a template and dopamine as carbon and nitrogen precursor. A series of NHCPs-x samples with different pyrolysis temperatures were reported. The composite material formation was characterized by detailed methods (e.g., X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy). Results indicated that NHCPs treated at 750 °C with highest amounts of pyrindinic N showed improved electro-catalytic activity for nitrobenzene (NB) in neutral solution. NHCPs-750 can be developed as an effective sensing platform for the detection of NB, which showed high activity and superior analytical performance, such as a wide linear range of 5–2610 μM, a high sensitivity of 436 μAmM −1 , and a low limit of detection of 2.29 μM. [ABSTRACT FROM AUTHOR]

One-dimensional ZnO@In 2 O 3 core@shell nanofibers (CSNFs) were synthesized via a facile coaxial electrospinning method followed by high-temperature pyrolysis treatment. The obtained nanofibers have a well-defined core@shell structure with ZnO as the core and In 2 O 3 as the shell. Compared with the pure ZnO nanofibers and pure In 2 O 3 nanofibers, the ZnO@In 2 O 3 CSNFs based sensor presents the highest response to ethanol (31.87 at 100 ppm) at an operating temperature of 225 °C, which can be ascribed to the formation of a completely electron depletion layer in In 2 O 3 shell. Moreover, the ZnO@In 2 O 3 CSNFs based sensor also demonstrates outstanding selectivity, excellent stability and low detection limitation (∼5 ppm) to ethanol vapor. The ultraviolet photoelectron spectroscopy confirms a type-II heterojunction formed at the interface of ZnO core and In 2 O 3 shell. The main mechanism for the enhanced performance of ZnO@In 2 O 3 CSNFs gas sensor is the depletion modulating of In 2 O 3 shell layer in electron transfer. These results are valuable for the practical application of ZnO@In 2 O 3 CSNFs in ethanol detection. [ABSTRACT FROM AUTHOR]

The use of metal-free graphite carbon nitride (CN) to activate peroxymonosulfate (PMS) has attracted extensive attention for organic pollutants degradation. In this work, we prepared carbonized polydopamine-decorated g-C 3 N 4 (CP-700) for activation of PMS to degrade norfloxacin (NOR). The CP-700 composite was obtained by using CN as a base material on which dopamine underwent an autopolymerization reaction to form a CN-PDA complex, followed by pyrolysis. The apparent porous structure and graphitization provided a large number of active sites for catalytic degradation, enabling CP-700 to exhibit excellent catalytic performance during PMS activation. The degradation of NOR was not hindered by sulfate radical (SO 4 •–) and hydroxyl radical (•OH). Singlet oxygen (1O 2) and mediated electron transfer were ultimately identified as the primary mechanisms. According to the linear positive correlation (R2 = 0.9922) between the semi-quantitative carbonyl group (C O) and the reaction rate constant, it was determined that the carbonyl group served as the important active site. The excellent electron transfer ability of CP-700 was evidenced by electrochemical techniques and the electron transfer pathway in the system was that PMS was adsorbed on the CP-700 surface to form metastable complex, and then the electron transfer between NOR and metastable complex was achieved. Based on the non-radical pathway, CP-700/PMS system showed a high tolerance to solution pH (3.0–11.0) and inorganic anions. The cyclic degradation experiments indicated that the system maintained a high degradation capability without the addition of additional CP-700, elucidating its potential application in the degradation of organic pollutants in the water. [Display omitted] • CP-700 had a better catalytic reactivity than CN-700 at a lower dosage. • 1O 2 was the primary reactive oxygen species responsible for NOR degradation. • Carbonyl groups and graphitic N served as the main active sites for PMS activation. • CP-700/PMS system exhibited excellent pH tolerance and more effective use of PMS. [ABSTRACT FROM AUTHOR]

[Display omitted] • An anti-perovskite Ni 3 FeN/VN heterostructure is designed for Zn-air batteries. • The anti-perovskite Ni 3 FeN with the metallic behavior contributes to electron transfer. • Abundant catalytic active sites are formed at the heterogeneous interface. • The Ni 3 FeN/VN–NG displays excellent bifunctional activity with a ΔE value of 0.69 V. High-performance rechargeable zinc–air battery is highly relying on the efficient and stable bifunctional electrocatalysts. Herein, an anti-perovskite Ni 3 FeN/VN heterostructure encapsulated N–doped graphene (Ni 3 FeN/VN–NG) was synthesized by a two-step transformation of trimetallic NiFeV–layered double hydroxide. The Ni 3 FeN/VN–NG showed excellent bifunctional catalytic activity (ΔE = 0.69 V) and stability. The excellent bifunctional electrocatalytic performance is benefited from the extraordinary catalytic behavior of Ni 3 FeN/VN heterostructure. The intrinsic metallic properties and remarkable superconductivity of anti-perovskite Ni 3 FeN can enhance the electrocatalytic performance. Density functional theory calculations confirm that the electronic coupling between Ni 3 FeN and VN facilitates the charge transfer between the two components, simultaneously generates abundant catalytic active sites at the heterogeneous interface. When the Ni 3 FeN/VN–NG was used as the air cathode, in zinc–air battery, the zinc–air battery exhibits a high-power density of 168 mW cm−2 and a long cycle life of over 200 h. [ABSTRACT FROM AUTHOR]

[Display omitted] • A self-adhesive tannin–graphene supramolecular pH-sensitive material is proposed. • The material adheres well to various solid and soft substrates. • The sensor exhibits reversible, Nernstian and selective pH responses. • The material can be printed directly to fabricate a wearable sensor for sweat pH monitoring. The pH of sweat is the most common biochemical parameter monitored by integrated wearable devices. A crucial factor in sensing materials for wearable applications is strong contact both with the skin and with the electrode substrate. Currently, the deposition of many sensitive materials on a substrate relies on mixing a small amount of binder, which raises the issue of biocompatibility and the risk of detachment. Herein, we report self-adhesive tannin–graphene supramolecular aggregates for use in wearable potentiometric pH sensors. The abundant phenolic hydroxyl groups in tannin (TA) result in strong adhesion and are also the pH response sites. The graphene (reduced graphene oxide, RGO) induces the supramolecular formation of TA and promotes electron transfer based on the π-π conjugation interaction. The pH sensor has a reversible and Nernstian response, and is not affected by potentially interfering ions. Owing to the strong adhesion of TA–RGO, a wearable pH device was directly fabricated using a dispensing printing technique. The sensor has been shown to be successful in monitoring the pH of sweat in real time. This work emphasizes the importance of the adhesion of sensing materials for use in wearable electrochemical sensors. [ABSTRACT FROM AUTHOR]

A series of N-doped graphitic carbons with different carbonization temperatures (denoted as ENGC-T) are controllably synthesized. The correlation between different N-doping species and interlayer spacing is explored, and thus demonstrating that pyrrolic-N (N-5) content has a substantial effect of the expanded interplanar spacing. The resulting ENGC-850 with the optimal N-5 configuration achieves excellent electrochemical performance in terms of capacity, rate capability, and cycling stability. [Display omitted] • A series of N-doped graphitic carbons are controllably synthesized. • High edge-N doping ratio is conducive to promote capacitive-controlled K-storage. • Pyrrolic-N configuration has a substantial effect on the interlayer spacing. • The resultant product delivers excellent rate capability and exceptional cyclability. Nitrogen (N) doped graphitic-carbon materials as anode have been intensively studied for potassium-ion batteries (PIBs). However, insufficient N-doping content, especially the low edge-N ratio composed of pyridinic-N (N-6) and pyrrolic-N (N-5) cannot provide excellent rate capability and ultra-long cycle lifespan. Meanwhile, the intercorrelation between N-doping species and enlarged interlayer spacing remains unclear and needs to be further explored. Based on this, a series of N-doped graphitic carbons with different carbonization temperatures (denoted as ENGC-T) are controllably synthesized. It is found that a high edge-N doping ratio is conducive to increase active sites to promote capacitive-controlled K-storage. And the correlation between N-doping species and interlayer spacing reveals that N-5 configuration has a substantial effect on the interlayer spacing, due to its stronger electrostatic repulsion. Accordingly, the resultant ENGC-850 with both an ultra-high edge-N ratio (76.6%) and N-5 content (42%) achieves the most abundant defects and the largest interspacing, ensuring high capacity and cycling stability. Besides, good crystallization characteristics guarantees fast electron transfer, favoring conductivity. As expected, ENGC-850 electrode delivers high capacity, excellent rate (228.9 mAh g−1 at 2 A g−1), and prolonged cycle lifespan (188.9 mAh g−1 over 2200 cycles). [ABSTRACT FROM AUTHOR]

The use of La 1−x Sr x FeO 3 (x= 0, 0.1, 0.2, 0.3, 0.4 and 0.5) cathodes in asymmetric electrocarboxylation of acetophenone with CO 2 induced by chiral auxiliary CoII-(salen) was investigated for the first time. Optically active 2-hydroxy-2-phenylpropionic acid with 94% enantiomeric excess and 68% yield were obtained. The superior asymmetric electrocarboxylation performance may derive from the Fe4+ species and the increased lattice oxygen concentration on the surface of La 0.7 Sr 0.3 FeO 3 (LSF-0.3) induced by Sr-doping, together with an accelerated electron transfer and an increased electrochemically active surface area. Here, perovskite oxide catalyst has an acid function, which is supplied by Fe4+ ions, can participate in the reaction by coordinating with acetophenone. Moreover, the LSF-0.3 has considerable stability and reusability. By cyclic voltammograms and contrast experiments, a mechanism was proposed for the asymmetric electrocarboxylation reaction. [Display omitted] The superior asymmetric electrocarboxylation performance for La 0.7 Sr 0.3 FeO 3 cathode may stem from the increased concentration of O2– and Fe4+, together with an accelerated electron transfer and an increased electrochemically active surface area. [ABSTRACT FROM AUTHOR]

• The signal indicator and matrix, Fe 3 S 4 -Pd, displayed excellent electrocatalytic activity for H 2 O 2 redox reaction. • Magnetic glassy carbon electrode was used to firmly immobilized the magnetic Fe 3 S 4 -Pd to achieve satisfied stability. • PBG nanomaterial played a role as the electron blocking label that realized a sensitive variation of current signal. • The signal-off sensing platform was successfully constructed, with a low detection limit of 130 fg/mL. Herein, a sandwich-type electrochemical (EC) immunosensor is proposed based on a special signal-off mode for the sensitive detection of procalcitonin (PCT) by utilizing Fe 3 S 4 loaded with Pd nanoparticles (Fe 3 S 4 -Pd) as a signal indicator and matrix and functionalized pineal mesoporous bioactive glass (PBG) as the label for signal amplification. Fe 3 S 4 -Pd not only shows excellent electrocatalytic activity for the H 2 O 2 redox reaction but is also firmly immobilized on a magnetic glassy carbon electrode due to its excellent magnetic properties; because of the above features, this immunosensor exhibits excellent sensitivity and stability, respectively. Glutaraldehyde is used as a cross-linking agent to bond the secondary antibodies (Ab 2) with PBG. It is worth mentioning that the electron transfer rate between the electrolyte and electrode is decreased significantly by PBG-Ab 2 ; thus, a sensitive variation in the current signal is observed, and a further improvement in the sensitivity of the immunosensor is realized. More importantly, the proposed signal-off sensing system has a wide linear detection range of 500 fg/mL to 50 ng/mL for PCT and a low detection limit of 130 fg/mL, which promotes it as a promising detection method for the sensitive detection of other biomarkers. [ABSTRACT FROM AUTHOR]

To explore a green, low-cost, and efficient strategy to synthesis reduced graphene oxide (RGO), the process and mechanism of the graphene oxide (GO) reduction by a model electrochemically active bacteria (EAB), Geobacter sulfurreducens PCA, were studied. In this work, up to 1.0 mg mL−1 of GO was reduced by G. sulfurreducens within 0.5–8 days. I D /I G ratio in reduced product was similar to chemically RGO. After microbial reduction, the peak which corresponded to the reflection of graphene oxide (001) disappeared, while another peak considered as graphite spacing (002) appeared. The peak intensity of typical oxygen function groups, such as carboxyl C–O and >O (epoxide) groups, diminished in bacterially induced RGO comparing to initial GO. Besides, we observed the doping of nitrogen and phosphorus elements in bacterially induced RGO. In a good agreement with that, better electrochemical performance was noticed after GO reduction. As confirmed with differential pulse voltammetry (DPV) and cyclic voltammetry (CV) analysis, the maximum value of peak currents of bacterially induced RGO were significantly higher than those of GO. Our results showed the electron transfer at microbial cell/GO interface promoted the GO reduction, suggesting a broader application of EAB in biological mediated production of RGO. Image 1 • Provided a green chemistry strategy for the biological production of reduced graphene oxide (RGO) by Geobacter. • Bacterially induced RGO by Geobacter exhibited a good performance in electrochemical conductivity. • The doping of nitrogen and phosphorus elements were observed in the bacterially induced RGO by Geobacter. • Extracellular electron transfer at microbial cell/GO interface promoted the graphene oxide (GO) reduction of Geobacter. [ABSTRACT FROM AUTHOR]

In this study, the optimized CdS/Ni-MOF photocatalyst with considerable activity and good stability for H 2 evolution was obtained by in-situ growth of CdS nanoparticles on the surface of Ni-MOF. Ni-MOF as an ideal support hinders the aggregation of CdS during the synthesis period. As a noble-metal-free catalyst, the obtained CdS/Ni-MOF composite having an optimal CdS loading of 40 wt% exhibits a remarkable H 2 production rate of 2508 μmol/g/h under visible light, which is about eight times higher than that of single CdS. The CdS/Ni-MOF composites generate electron-hole pairs under visible light. Then, the photo-generated charges in the CB of CdS are directly transferred to Ni-MOF due to the interface contact and the matched positions of the CB of CdS and the LUMO of Ni-MOF, and the holes are consumed by the sacrificial agent (lactic acid). In this case, electron-hole pairs are effectively separated, Moreover, Ni-MOF containing highly dispersed Ni2+ irons could act as the active site for H 2 generation. Ni-MOF acts as a dual role of electron acceptor and co-catalyst in photocatalytic H 2 production from water. This work could pave the way for further development of semiconductor/MOF composites with enhanced-performance. • The CdS/Ni-MOF composites are successfully synthesized. • The CdS/Ni-MOF composites exhibit high charge separation efficiency. • The CdS/Ni-MOF composites offered enhanced performance in photocatalytic H 2 production. Constructing semiconductor-based photocatalysts with high-performance and excellent stability is a promising approach to achieve optimum photocatalytic H 2 production rate from water splitting. In this study, a novel effective visible-light-driven catalyst, namely, CdS/Ni-MOF, has been successfully synthesized by in-situ growth of CdS nanoparticles on the surface of hollow Ni-based metal-organic framework (Ni-MOF) spheres. The heterogeneous interface contact and matched band position promote charge separation. As a noble-metal-free catalyst, the obtained CdS/Ni-MOF composite having an optimal CdS loading of 40 wt.% exhibits a remarkable H 2 production rate of 2508 μmol/g/h under visible light, which is about eight times higher than that of single CdS. Ni-MOF serves as a station for the rapid transfer of photo-induced electrons, leading to the high photocatalytic performance. Meanwhile, Ni-MOF comprising highly dispersed Ni2+ catalytic sites also acts as co-catalyst, which is beneficial for hydrogen evolution. Therefore, Ni-MOF functions as both an electron acceptor and a co-catalyst in the photocatalytic H 2 production from water. This work highlights the advantages of combining semiconductor and MOF functionalities to fabricate a photocatalyst with enhanced catalytic activity. [ABSTRACT FROM AUTHOR]

• A PEC aptamer sensor for 17β-estradiol detection was introduced. • The Mo doped porous BiVO 4 nanoarray/Bi 2 S 3 as sensing platform for immobilization of aptamer. • The Mo-p BiVO 4 /Bi 2 S 3 presented a high PEC signal by supplying additional free electrons. • The nanoarray structure provided large specific surface area and large number of binding sites. • The PEC aptamer sensor exhibited a low detection limit of 3.2 × 10−4 pM. A new porous nanoarray is constructed as sensing platform of photoelectrochemical (PEC) biosensor for detection of 17β-estradiol (E2) by using aptamer. The molybdenum (Mo) ions doped into porous bismuth vanadate (Mo-p BiVO 4) nanoarray by electrodeposition of BiOI nanoarray. Then, the bismuth sulfide (Bi 2 S 3) nanoparticles are grown in-situ on the surface of Mo-p BiVO 4 by the self-sacrificial synthesis method to form novel Mo-p BiVO 4 /Bi 2 S 3 heterojunction. Herein, the Mo-p BiVO 4 /Bi 2 S 3 heterojunction presents a high PEC signal because of Mo-p BiVO 4 could increase electron-hole separation yield by supplying additional free electrons, furthermore the heterojunction of Mo-p BiVO 4 /Bi 2 S 3 could promote ultrafast transfer of charge and inhibit the recombination of e−/h+ pairs by presenting cascade band-edge levels under irradiation of the visible light. Moreover, the nanoarray structure has large specific surface area, which could accelerate electron transfer and provide large number of binding sites to immobilize aptamer. This PEC aptamer sensor exhibits high sensitivity with a detection limit 3.2 × 10-4 pM and a good photocurrent response toward target E2 in the range of 1 × 10-3 - 5 × 102 pM. Good specificity and stability are acquired for analysis of E2 in human urine. Importantly, this designed sensor platform of Mo-p BiVO 4 /Bi 2 S 3 heterojunction provides a new promising application for other environmental estrogen analysis. [ABSTRACT FROM AUTHOR]

• A sandwich-type immunosensor for detection of PCT was designed. • CeO 2 -CuO-Au as platform can promote electron transfer. • Au@Ag-Th as signal labels can further effectually amplify the current signal. • The immunosensor presents prominent performance for PCT detection. Procalcitonin (PCT) is a kind of protein exists in the human blood. If the human bodies are infected with bacteria, fungi or parasites, the value of PCT in blood will be significantly raised. Thereby, we report an electrochemical immunosensor for measurement of PCT using gold nanoparticle (Au NP) decorated CeO 2 -CuO (CeO 2 -CuO-Au) as the platform and thionine modified Au@Ag heterojunction nanorods (Au@Ag-Th) as signal labels. Au NP decorated CeO 2 -CuO exhibits high surface area, high activity and good biocompatibility, which can immobilize more primary antibodies and promote electron transfer. The Au@Ag-Th provides good active sites to link secondary antibodies, further effectually amplify the current signal. This immunosensor exhibits a well-pleasing response with a limit detection of 0.17 pg mL−1 and linear detection between 0.5 pg mL−1 and 50 ng mL−1. Meanwhile, the high sensitivity, excellent specificity and acceptable human serum samples testing results of this method lead to potential applications in diagnosis of bacterial infections. [ABSTRACT FROM AUTHOR]

A signal-off type photoelectrochemical (PEC) immunosensor based on Ru(bpy) 3 2+ and Bi 2 S 3 co-sensitized ZnTiO 3 /TiO 2 polyhedra as matrix and SiO 2 /PDA-Au as the label of second antibody was proposed for the ultrasensitive detection of procalcitonin (PCT). The hollow ZnTiO 3 /TiO 2 polyhedra called zinc titanium composite hollow structures (ZTCHS) was prepared by hydrothermal method to enhance the utilization of visible light comparing with pure ZnTiO 3 or TiO 2. The unique structure endowed large specific surface areas and satisfying load capacity to ZTCHS. Ru(bpy) 3 2+ and Bi 2 S 3 were utilized to co-sensitize ZTCHS to further strengthen the PEC performance of ZTCHS. It was interesting that the dual-inhibition effects of SiO 2 /PDA-Au further enhanced the sensitivity of proposed PEC immunosensor. On the one hand, the steric hindrance of SiO 2 /PDA effectively restricted electron transfer. On the other hand, Au nanoparticles could absorb visible light to compete with the matrix material. Based on the above aspects, the proposed signal-off type PEC immunosensor possessed a wide linear range from 0.0001 ng mL−1 to 100 ng mL−1 and low detection limit (about 0.03 pg mL−1, S/N = 3), demonstrating the promising application of PEC immunosensor in analysis fields. ► Novel Ru (bpy) 3 2+ and Bi 2 S 3 sensitized ZTCHS polyhedra shows excellent PEC activity. ► The dual-inhibition effects of SiO 2 /PDA-Au reduce distinctly the photocurrent. ► A signal-off type PEC sensor achieves the ultrasensitive detection of procalcitonin. [ABSTRACT FROM AUTHOR]