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• Phosphorene quantum dot modified prussian blue (PB) skeleton has been synthesized. • CN– groups passivate edges of phosphorene quantum dot (BP) to improve its stability. • CN– group can desire the band edge positions of BP to improve its catalytic activity. • PB skeleton can support BP to inhibit its agglomeration and transport the electron. • This nanostructure used as highly efficient electrocatalyst for hydrogen evolution. Facile liquid precipitation method assisted by liquid phase stripping has been used to prepare phosphorene quantum dot modified prussian blue porous skeleton structure. In this structure, the CN– group in prussian blue has larger chemical electronegativity than phosphorus atom, which can not only passivate the edges of phosphorene nanostructure, but also desire the valence band maximum and conduction band minimum band edge positions of black phosphorus for hydrogen generation in electrocatalytic water splitting. Moreover, the prussian blue porous network can be used as the support for phosphorene quantum dot and the medium for electron transport. This prussian blue supported phosphorene quantum dot porous network exhibits enhanced electrocatalytic hydrogen evolution performance with an over-potential of 148 mV at −10 mA cm−2 and a Tafel slope of 79 mV dec−1, which drastically surpass those of the black phosphorus. In addition, both the consecutive cyclic voltammetry and potentiostatic test reveal the outstanding electrocatalytic stability of the composite. This construction based on edge-modified phosphorene nanostructure presents efficient electrocatalys activity for water splitting. [ABSTRACT FROM AUTHOR]

Hexagram-like CoS-MoS composites were prepared on indium tin oxide (ITO) conductive glasses via cyclic voltammetry electrodeposition using Co(NO) and (NH)MoS as precursors and tested for application in hydrogen evolution reaction (HER). The structure of CoS-MoS composites was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and X-ray photoelectron spectrum (XPS). Electrochemical characterizations indicate that CoS-MoS composites exhibit more excellent catalytic activity and stability than MoS. Compared with pure MoS, the hexagram-like CoS-MoS composites with increased specific surface area improved the density of exposed active sites, and the Co binding S edges in CoS-MoS composites promote the number of highly catalytic edge sites and decreased the binding energy △ G . Moreover, the effects of different substrates on the CoS-MoS composites were also investigated. Our further understanding of this highly active hydrogen evolution catalyst can facilitate the development of economical electrochemical hydrogen production systems. [ABSTRACT FROM AUTHOR]

Dendritic MoO3/Ag with good crystallinity has been prepared through an operando method. In the hydrogen evolution reaction (HER), this catalyst, which was designed to utilize the best properties of each component material, showed a high catalytic activity. After the precursor was drop-cast onto a glassy carbon electrode, a reductive potential was applied to the coated electrode, and H2 evolution occurred within the range of potentials. The overpotential required to evolve H2 at the benchmark rate decreased progressively with subsequent voltammetric cycles, until a steady state was reached at which only 145 mV of overpotential was required to pass −10 mA cm−2 of current density. During the electrocatalysis, the precursor was converted to catalyst through an operando method. This operando-synthesized MoO3/Ag catalyst has a low Tafel slope (43 mV dec−1), low overpotential (145 mV), and excellent durability for HER. It has the potential to be a promising material for HER. [ABSTRACT FROM AUTHOR]

Abstract: MoS2-carbon composites which with different morphologies were synthesized by hydrothermal method and tested with respect to their application in hydrogen evolution reaction (HER). Their performances were compared to evaluate how the morphology influence HER. The obtained results showed that the composite containing amorphous MoS2 showed higher activity than composite which contains crystalline MoS2. The catalytic activity of composite was highly correlated to its active surface area which was controlled by the morphology. In addition, compared with composite which contains amorphous MoS2, the composite containing crystalline MoS2 showed higher durability in the long-term operation. However, in acidic and alkaline environments, the stability of composite containing amorphous MoS2 is better than which containing crystalline MoS2. The impedance measurements suggested that the high catalytic activity of the composite stems from the synergistic effect of MoS2 and carbon materials. The enhanced understanding of these highly active hydrogen evolution catalysts can facilitate the development of economical electrochemical hydrogen production systems. [Copyright &y& Elsevier]

In this study, we designed a Pt/CoFe 2 O 4 /NC composite material as an excellent electrocatalyst for hydrogen evolution reaction (HER) and used the HER signal to construct an electrochemical immunosensor for carcinoembryonic antigen (CEA) detection. Remarkably, Pt/CoFe 2 O 4 /NC demonstrated superior HER performance compared to alternative Pt-based materials. It exhibited a low overpotential of only 42 mV and a Tafel slope of 253 mV dec−1 in acidic medium. Furthermore, due to the excellent conductivity, large surface area, and superior HER performance of Pt/CoFe 2 O 4 /NC, it was used as secondary antibody (Ab 2) label to achieve signal amplification in the electrochemical immunosensor. The results showed that this immunosensor possessed high selectivity and sensitivity. The linear detection range is 1.0 × 10−4–5.0 ng mL−1, and the detection limit is 0.0134 pg mL−1. It has potential applications in the clinical analysis field. Due to the excellent conductivity, large surface area, and superior HER performance of Pt/CoFe 2 O 4 /NC, it was used as an Ab 2 label to achieve signal amplification in the electrochemical immunosensor. The results showed that this immunosensor possessed high selectivity and sensitivity. The linear detection range is 1.0 × 10−4–5.0 ng mL−1, and the detection limit is 0.0134 pg mL−1. It has potential applications in the clinical analysis field. [Display omitted] • Pt is loaded onto the CoFe 2 O 4 /NC by photoreduction method. • The Pt/CoFe 2 O 4 /NC with low Pt loading presents low overpotential and Tafel slope in the HER. • A novel electrochemical immunosensor based on Pt/CoFe 2 O 4 /NC was constructed for CEA detection. [ABSTRACT FROM AUTHOR]

Few study has been carried out on the construction of immunesensors utilized the photoelectric and catalytic signal of nanomaterial. Here, a dual-signal electrochemical immunosensor was constructed for procalcitonin (PCT) detection based on the excellent photoelectric and hydrogen evolution performance of molybdenum-doped cobalt-iron sulfur nanosheets modified by platinum nanoparticles (Pt/Mo–CoFeS). Due to the electronic structure regulation between Pt and Mo–CoFeS, Pt/Mo–CoFeS exhibits superior photoelectric and hydrogen evolution performance compared to single Mo–CoFeS, which improved the sensitivity of the electrochemical immunosensor. Furthermore, the presence of Pt improves surface area and biocompatibility, achieving more antibodies loading and signal amplification. The linear range of PCT detection are 0.002–20 ng mL−1 and 0.002–50 ng mL−1, the detection limits are 0.0015 and 0.0012 ng mL−1. In addition, this electrochemical immunosensor was applied to the PCT analysis in human serum samples with high recoveries. F-test and t -test show that there is no significant difference in the test results between the HER and photoelectric signals, the mutual verification between above two signals can effectively improve the accuracy of detection result. Bifunctional catalyst Pt/Mo–CoFeS for water electrolysis and photoelectric conversion was prepared and used as a signal marker to construct a dual-signal electrochemical immunosensor for procalcitonin detection. Results show that this dual-signal electrochemical immunosensor with wide detection linear range (0.002–50 ng mL−1) and low detection limits (HER signal: 0.0015 ng mL−1 and photoelectric signal: 0.0012 ng mL−1), and the mutual verification between above two signals can effectively improve the accuracy of detection result. [Display omitted] • Dual-signal electrochemical immunosensor was constructed based on Pt/Mo–CoFeS. • The electronic regulation between Pt and Mo–CoFeS improve its HER and photoelectric performance. • PCT detection based on the immunosensor with wide linear range and low detection limit. • F-test and t -test show that there is no significant difference in these two test results. [ABSTRACT FROM AUTHOR]

Making full use of photogenerated charge carriers by careful design multifunctional photocatalysts to achieving bi-value-added production with high-efficiency is highly desirable and extremely challenge. Herein, a novel 2D/3D ZnIn 2 S 4 @Ni 1 /UiO-66-NH 2 (ZIS@Ni 1 /UN) heterojunction with spatially separated and precise redox sites was designed and fabricated for both photocatalytic H 2 production and benzyl alcohol (BA) valorization. By precise structural regulation and modification of UiO-66 integrated with -NH 2 , ZnIn 2 S 4 (ZIS) and Ni single-atom, the spatial separation of redox sites and directional electron transfer has been achieved. This realizes collaborative and efficient solar energy to chemical energy conversion. The optimal sample 5ZIS@Ni 1 /UN-6 shows high photocatalytic H 2 and benzaldehyde (BAD) production rates of 11.44 mmol∙g−1∙h−1 and 10.02 mmol∙g−1∙h−1 under visible light. This work highlights the importance of rational construction for the engineering of charge behavior in heterogeneous photocatalysts with spatial separation and identifies their crucial role in promoting the photocatalytic redox coupling reactions. [Display omitted] • A novel 2D/3D ZnIn 2 S 4 @Ni 1 /UiO-66-NH 2 heterojunction is successfully design and fabricated. • High production rates of benzaldehyde and H 2 simultaneous is achieved under visible-light. • Precise construction of spatially separated redox-sites and directional electron transfer synergistically boost photocatalytic performance. • The carbon-centered free radical process of selective oxidation of benzylalcohol is confirmed by in-situ EPR. [ABSTRACT FROM AUTHOR]

Metal oxide semiconductor heterojunctions and homojunctions are considered to have better performance than single phase material for room temperature hydrogen gas sensing. In this work, TiO 2 facet homojunction (TiO 2 -FH) thin films were prepared by a two-step hydrothermal method. The TiO 2 -FH thin films were decorated with Pt nanoparticles using a green photodeposition method and then evaluated for H 2 sensing. Non-noble metal Al was used as finger electrodes instead of noble metal Pt. Compared with the TiO 2 -FH sensor, the H 2 detection limits of the platinum loaded TiO 2 -FH@Pt sensors are remarkably decreased from 8000 ppm to 1 ppm at room temperature. The optimized sensor achieves an excellent sensing performance of S = 1.21 and fast response / recovery times of about 42 s / 30 s when exposed to 1 ppm H 2 concentration. The synergy between the Schottky barrier at the Pt/TiO 2 interface and the barrier between the (110) and (001) facets of TiO 2 is the key to the improvement of the sensing performance. Replacement of noble metal Pt with Al and C electrodes greatly help to clarify the mechanism of the junctions in the thin film sensors, especially the function of the Pt/TiO 2 junction and the (110)/(001) TiO 2 junction. The simple and green fabrication method and cheap Al interdigitated electrodes are advantageous for practical applications. • Noble metal electrodes of gas sensors were substituted by non-noble metal Al and C. • Trace Pt decorated TiO 2 homojunction was designed for hydrogen sensing. • The sensors maintain the wide detection range and high response. • The Schottky barrier at Pt/TiO 2 interface is the main factor for the sensing performance. • The function of the barrier between the (110) and (001) facets of TiO 2 is clarified. [ABSTRACT FROM AUTHOR]

[Display omitted] • (NiFeCo) 2 P@Au/CeO 2 generates strong HER and OER signals in neutral environment. • Dual-signal sensor was constructed using (NiFeCo) 2 P@Au/CeO 2 as electrocatalytic label. • HER and OER signals of this electrochemical immunosensor can be mutually verified. Sensitive and accurate detection of prostate-specific antigen (PSA) is great importance for the diagnosis and treatment of prostate cancer. However, constructing an electrochemical immunosensor with dual-signal detection can significantly improve the sensitivity and accuracy of PSA detection. Therefore, we prepared an electrolytic water bifunctional catalyst (NiFeCo) 2 P@Au/CeO 2 and used it as an electrocatalytic label to construct a dual-signal electrochemical immunosensor. Based on the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) signals of (NiFeCo) 2 P@Au/CeO 2 , the electrochemical immunosensor can achieve dual-signal detection of PSA. Research has shown that the dual-signal electrochemical immunosensor not only has a wide detection linear range (0.0001–100 ng mL−1), but also has extremely low detection limits (HER signal: 116.86 fg mL−1 and OER signal: 39.05 fg mL−1). In addition, it was used for PSA detection in human serum samples with good recovery. This dual-signal electrochemical immunosensor provides a new detection method for PSA and also develops a new dual-signal detection strategy for electrochemical immunosensor. [ABSTRACT FROM AUTHOR]

In recent years, noble metal catalysts have been extensively studied in terms of hydrogen evolution reaction (HER), but there has been less research on the construction of immunosensor based on the catalytic signal amplification strategy of noble metal. Based on the excellent HER and photoelectric performance of AuPt nanoslices modified black phosphorus nanoflakes (AuPt/BP) in neutral medium, we reported a dual-signal electrochemical immunosensor, which uses AuPt/BP as signal amplification label for the detection of procalcitonin (PCT). Due to the charge transfer between AuPt and BP, AuPt/BP has better HER activity and photoelectric performance than single AuPt or BP, which realized the construction of dual-signal electrochemical immunosensors and the improvement of detection sensitivity. In addition, the presence of BP makes AuPt/BP has better dispersion and larger surface area, which can load more secondary antibody (Ab 2) and realize the signal amplification of the immunosensor. The linear ranges of PCT detection based on HER and photoelectric signals are 1.96 fg mL−1 ∼ 0.196 ng mL−1 and 1.96 fg mL−1 ∼ 19.6 pg mL−1, and the detection limits of PCT with HER and photoelectric signals are 0.88 fg mL−1 and 0.99 fg mL−1. [Display omitted] • A dual-signal electrochemical immunosensor has been constructed for procalcitonin detection. • AuPt/BP with excellent electrocatalytic hydrogen evolution and photoelectric signals. • The synergy of various phases improve the HER performance of AuPt and stability of BP. • This electrochemical immunosensor exhibits a satisfied linear range and detection limit. [ABSTRACT FROM AUTHOR]

• Highly dispersed pseudoamorphous metal phosphide ((NiFeCo) 2 P-PA) have prepared. • The formation of pseudoamorphous catalyst was promoted by hydrothermal process. • Pseudoamorphous structure has more active sites and higher intrinsic activity. • (NiFeCo) 2 P-PA has excellent water electrolysis stability under industrial current. • DFT calculation shows that the pseudoamorphous catalyst has lower OER energy barrier. Industrial hydrogen production based on water electrolysis requires the catalysts that operate stably at ultra-high current densities for extended periods. Herein, we prepared a highly dispersed pseudoamorphous metal phosphide cluster catalyst supported by nitrogen-doped carbon layer ((NiFeCo) 2 P-PA/NF). Due to its excellent intrinsic activity and stable structure, (NiFeCo) 2 P-PA/NF can drive oxygen evolution unremittingly for more than 160 h at a current density of 500 mA cm−2 (365 mV). Theoretical calculations also show that the energy barrier of the rate-determining step in the (NiFeCo) 2 P-PA is effectively is reduced. This alkaline hydrogen production system using (NiFeCo) 2 P-PA/NF as cathode and anode can meet commercial standards, showing low cell voltage (1.590 V) and extraordinary stability (over 300 h) at industrial current densities, and driving a cell voltage of only 1.372 V for 100 mA cm−2 in the urea alkaline hydrogen production system, demonstrating its potential for industrial applications. [ABSTRACT FROM AUTHOR]

A promising Pt@Te nanoparticles catalyst has been synthesized on the surface of the reduced graphene oxide/polyimide (rGO/PI) substrate. First of all, Te was deposited on the rGO/PI using electrochemical deposition method to obtain Te-rGO/PI that has various morphologies. Secondly, a monolayer Pb film was deposited on the Te-rGO/PI by the similar electrochemical method to get a transition state material of Pb@Te-rGO/PI. Finally, the target Pt@Te catalyst on the rGO/PI with large surface area was obtained by a chemical oxidation method, in which Pb was stripped off from the Pb@Te-rGO/PI by an oxygenation of H 2 PtCl 6 , while the oxygenation process, Pt replaced Pb to be deposited on the surface of Te-rGO/PI to form Pt@Te-rGO/PI. Then the prepared Pt@Te-rGO/PI was used as a working electrode to study the hydrogen evolution behavior in 0.5 mol/l H 2 SO 4 . By comparison the catalyst of sole Pt-rGO/PI nanoparticles, Pt@Te-rGO/PI catalyst considerably abated the demanding of Pt. And it shows excellent HER activities with a low overpotential of 0.1 V. The Tafel slope of 55 mV dec −1 reveals most likely the Volmer–Heyrovsky mechanism for hydrogen evolution reaction (HER). On the other hand, the catalyst displays satisfactory stability. This work may pave a potential pathway for synthesizing multi-morphology nano-Pt catalyst with high surface area for application in the study of HER. [ABSTRACT FROM AUTHOR]

• A porous Mo-doped CoFe LDH/NF catalysts was prepared by electrochemical transformation Mo-doped CoFe PBA/NF. • Mo doping modulated the electronic structure of CoFe LDH/NF. • Catalysts only require 331 mV and 227 mV drive 100 mA cm−2 for OER and HER in alkaline medium. • The electrode pair shows high activity and durability in alkaline media at large current density. [Display omitted] Facile preparation of efficient, low-cost, and stable bifunctional electrocatalysts for overall water splitting remains a big challenge. Herein, we successfully synthesized Mo-doped CoFe layered double hydroxides (Mo-doped CoFe LDH/NF) nanosheets by electrochemical transformation of Mo-doped CoFe prussian blue nanocubes on nickel foam (Mo-doped CoFe PBA/NF) for highly efficient overall water splitting. The catalyst exhibits outstanding oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance after electrochemical transformation, which is due to the abundant edge defects of Mo-doped CoFe LDH/NF can expose more active sites. Meanwhile, Mo6+ has a strong electron absorption ability, which could adjust the electronic structure and stabilize the high valence active sites. It only requires a low overpotential for OER (331 mV) and HER (227 mV) to reach 100 mA cm−2 in alkaline media, respectively. Notably, when it was employed as a bifunctional electrode, Mo-doped CoFe LDH/NF displays a low potential of 1.55 V to reach 100 mA cm−2 coupled with long-term water splitting stability in an alkaline electrolyte. This work not only developed a novel method for the synthesis of efficient double-layer hydroxide catalysts, but also paved the way for the rational design of bifunctional electrocatalysts with practical application value. [ABSTRACT FROM AUTHOR]