Water electrolysis derived by renewable energy such as solar energy and wind energy is a sustainable method for hydrogen production due to high purity, simple and green process. One of the challenges ...is to reduce energy consumption of water electrolysis for large-scale application in future. Cell voltage, an important criterion of energy consumption, consists of theoretical decomposition voltage (Uθ), ohmic voltage drop (i⁎∑R) and reaction overpotential (η). The kinetic and thermodynamic roots of high cell voltage are analyzed systemically in this review. During water electrolysis, bubble coverage on electrode surface and bubble dispersion in electrolyte, namely bubble effect, result in high ohmic voltage drop and large reaction overpotential. Bubble effect is one of the most key factors for high energy consumption. Based on the theoretical analysis, we summarize and divide recent intensification technologies of water electrolysis into three categories: external field, new electrolyte composition and new thermodynamic reaction system. The fundamentals and development of these intensification technologies are discussed and reviewed. Reaction overpotential and ohmic voltage drop are improved kinetically by external field or new electrolyte composition. The thermodynamic decomposition voltage of water is also reduced by new reaction systems such as solid oxide electrolysis cell (SOEC) and carbon assisted water electrolysis (CAWE).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Rechargeable aluminum-ion batteries (AIBs), using a room temperature ionic liquid as the electrolyte and metallic Al as the anode, are very promising alternatives for large-scale electricity storage ...due to abundant aluminum sources, their high specific capacity, and their high safety. Cathode materials with both high capacity and low cost are of great importance for the achievement of such applications. Herein, copper phosphide (Cu3P) which is synthesized via a high-energy ball milling method is utilized for the first time as a novel cathode material for AIBs. It delivers high initial charge and discharge capacities of 139.1 and 73.8 mA h g−1 at 50 mA g−1, respectively, but shows poor cycling performance. After coating with acetylene black, the Cu3P/C composite exhibits a dramatically enhanced cycling stability. The charge–discharge mechanism of Cu3P is investigated using ex situ X-ray diffraction and X-ray photoelectron spectroscopy, which show that AlCl4− anions intercalate into Cu3P in the initial charge process, leading to the oxidation of Cu and P species. In the discharge process, the valence of the oxidized Cu remains unchanged while P is partially reduced. These findings are of great significance for the fundamental understanding of the Cu3P cathode for AIBs, as well as the further development of novel cathode materials of AIBs.
For exploring promising energy storage devices beyond lithium ion batteries, aluminum ion batteries (AIBs) are desirable cells with high energy-to-price ratios because of abundant natural resources, ...the higher energy density of aluminum and elimination of unexpected safety risks. Nevertheless, an ideal rechargeable AIB configuration with ultrahigh capacity is still fundamentally pursued. For fundamentally promoting the most promising chalcogen or chalcogenide-based AIB positive electrode materials, here rechargeable tellurium (Te) nanowire positive electrodes are demonstrated to construct novel tellurium-aluminum batteries. The cell configuration allows Te nanowires for delivering an ultrahigh discharge capacity ∼1026 mA h g
−1
(with a specific current of 0.5 A g
−1
) along with an initial 1.4 V discharge voltage, competitive with the record-setting energy density of the documented AIBs. For essentially tackling the dramatic capacity loss in tellurium positive electrodes, the mechanism of impacting the rechargeable ability is linked to the production of soluble tellurium chloroaluminate compounds upon both chemical dissolution and electrochemical conversion processes. As a consequence, the cell configuration is proved to substantially suppress the unexpected shuttle effects induced by soluble tellurium chloroaluminate compounds
via
employing reduced graphene oxide to support the tellurium positive electrodes as well as utilizing functionalized carbon nanotube membranes to modify the separators. The implication of the results suggests a nice plateau for massively promoting the rechargeable ability of AIBs, advancing remarkable routes for achieving ultrahigh capacity and energy density.
A novel cell configuration allows a Te nanowire positive electrode for delivering an ultrahigh discharge capacity in tellurium-aluminum batteries.
Porous NiMo film was prepared by one-step electrodeposition under super gravity field and was used as electrocatalyst for hydrogen evolution reaction (HER). NiMo films possessed three-dimensional ...porous structure. The thickness of porous layer was up to 180–240 μm. Porous NiMo films with extremely large real active area exhibited high catalytic activity for HER. The overpotential was very low and only 47 mV at 100 mA cm−2. Meanwhile, porous NiMo films possessed good long-term stability by accelerated degradation studies.
Porous NiMo films electrodeposited under super gravity possess extremely high real surface area and exhibit good catalytic activity for hydrogen evolution reaction. Display omitted
•Porous NiMo films are directly electrodeposited under super gravity field.•Good catalytic activity for HER was exhibited on porous NiMo films.•Porous NiMo films with high thickness possess extremely large real surface area.•Good long-term stability of porous NiMo films was obtained.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Electrochemical conversion of CO2 to carbon in molten salts is a promising route for the high-value utilization of greenhouse gases. Low graphitization degree of carbon materials is the limiting ...issue for potential applications. In the past, catalytic effect for the electrochemical conversion of CO2 was not achieved in molten salts due to carbon coverage on heterogeneous solid electrode. A novel and feasible homogeneous catalytic strategy by soluble NaVO3 in carbonate molten salt was proposed for the enhanced electrochemical conversion of CO2 to carbon with high graphitization degree. It was found that graphite consisting of carbon nanotubes and sheets were more easily produced by adding NaVO3 into molten salt. The graphitization degree of carbon products was obviously improved and ID/IG value was only 0.428. During CO2 electrolysis, vanadate in the form of V2O74− will be co-electroreduced to V2O3. Meanwhile, V2O74− ions can be regenerated by the spontaneous reaction between the newly-formed V2O3 and carbonate, which also accelerates the production of graphite. Therefore, a continuous homogeneous in-situ catalytic cycle was achieved for the enhanced graphitization conversion of CO2. It provides a novel and effective way to prepare carbon materials with high graphitization degree from CO2.
•Soluble NaVO3 was used as homogeneous catalyst for the electrochemical conversion of CO2 to graphite.•The graphitization degree of carbon products was obviously improved.•A continuous homogeneous in-situ catalytic cycle was achieved.•Graphite consisted of carbon nanotubes and sheets.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Because of the unprecedented development and popularization of portable electronics, electric vehicles, and smart grid, rechargeable batteries have become one of the hottest topics within worldwide ...research for the past decade. Among all of the proposed nonlithium-based battery systems, rechargeable aluminum-ion batteries (RAIBs) are considered as a promising candidate due to aluminum’s abundance and safety. Naturally, exploring compatible and high-performance cathode materials for RAIBs becomes a key issue for pushing RAIBs from lab-level to industrialization. In this work, we report a novel high-performance RAIB system using MOF-derived Co3O4@MWCNTs polyhedron composite as cathode. The well-defined morphology of MOF-derived Co3O4 and enhancement brought by MWCNTs allow Co3O4@MWCNTs polyhedrons to deliver an initial discharge capacity of ca. 266.3 mAh g–1, and the reversible specific capacity can reach 125 mAh g–1 at 100 mA g–1 over 150 cycles. The energy storage mechanism has been verified to be a reversible valence-change reaction between Co3O4 and Co. These findings can enlighten future research regrading MOF derivatives as advanced cathode materials for RAIBs.
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IJS, KILJ, NUK, PNG, UL, UM
High entropy alloys (HEAs) have attracted increasing attention because of their outstanding properties for various applications. During the preparation of HEAs, however, high-purity metals are ...usually used as raw material, which limits the large-scale application of HEAs. In this work, a simple electrochemical method is demonstrated to achieve homogeneous AlCrNbTaTi HEAs directly from metal oxide mixtures, and meanwhile the cathodic reduction mechanism is discussed. The patterns of both X-ray diffraction and selected area electron diffraction show that the as-prepared AlCrNbTaTi HEAs present body centered cubic structure. Upon electrolysis for 12 h, the oxygen content of the product is ∼0.6 wt% and the cathodic current efficiency is ∼46.7%. The results also suggest that the cathodic reduction process obeys a three-phase interline propagation mechanism, with the pellet surface initially metallized.
Self-supporting porous Ni film with uniform honeycomb-like micropores and a thickness of up to 66 μm is electrodeposited by dynamic hydrogen bubble template (DHBT) method in ultrasonic field. The ...dependence of ultrasonic power on porous structure and thickness of Ni films is investigated. The porous structure evolution mechanism is analyzed in terms of the effects of ultrasonic field on hydrogen evolution reaction (HER) and metal electrocrystallization. The HER catalytic performance of porous Ni films with different structure has also been studied. The results indicate that due to the acoustic cavitation and impact effect of ultrasonic waves, the nucleation of hydrogen bubble and the separation of hydrogen bubble from the electrode surface are improved, and the HER is enhanced. Then, self-supporting porous Ni film with uniform honeycomb-like micropores is formed. Too fast bubble separation is not conducive to the formation of porous structure. Moreover, in ultrasonic field, the current efficiency of Ni electrodeposition is increased owing to the enhanced mass transfer by ultrasonic-induced convection and hydrogen bubble agitation convection. Consequently, the thickness of porous Ni film is up to 66 − 89 μm. The porous Ni film electrodeposited in ultrasonic field with power of 250 W exhibits excellent HER catalytic performance due to the large activity area. Meanwhile, all the self-supporting Ni films possess a good long-term stability.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Human papillomavirus (HPV) infection can cause cervical and other cancers, including vulva, vagina, penis, anus, or oropharynx. However, in China's northern Henan Province, data on the prevalence and ...genotype distribution of HPV among women attending gynecology clinics is limited. This study aimed to investigate the current prevalence and genotype distribution of HPV among women attending gynecology clinics in northern Henan Province.
This study included 15,616 women aged 16-81 years old who visited the Xinxiang central hospital's gynecology department between January 2018 and December 2019. HPV DNA was detected by a conventional PCR method followed by HPV type-specific hybridization, which was designed to detect 17 high-risk HPV (HR-HPV) genotypes and 20 low-risk HPV (LR-HPV) genotypes. HPV prevalence and corresponding 95% confidence intervals (95% CI) were calculated using SPSS 18.0.
The overall HPV prevalence was 19.7% among women in northern Henan Province. Single, double, and multiple HPV infections accounted for 13.7%, 4.3%, and 1.8% of the total cases. Most infections were caused by HR-HPV (71.8%), and single genotype HPV infection (13.7%) was the most common pattern. The most common HR-HPV genotype was HPV16 (4.3%), followed by HPV52 (3.5%) and HPV58 (2.0%). The most common LR-HPV genotype was HPV6 (1.4%), followed by HPV61 (1.1%) and HPV81 (1.1%).
HPV infection is high among women attending gynecology clinics in northern Henan Province. The highest prevalence was found in women less than 20 years old. In northern Henan Province, the 9-valent HPV vaccine is strongly recommended for regular immunization.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Water electrolysis was carried out galvanostatically under a super gravity field. The relationships of cell voltage, ohmic voltage drop reduction and overpotential reduction with gravity coefficient ...(
G) and current densities were studied. It was found that water electrolysis was noticeably enhanced by the super gravity field. Good linear relationships between cell voltage (
U) and logarithm of
G can be obtained at all current densities. Large cell voltage reduction was achieved under the super gravity field, especially under higher gravity and at higher current densities. Energy savings were about 9–17% at 0.5
A
cm
−2 under the super gravity field. The cell voltage reduction was ascribed to ohmic voltage drop reduction and overpotential reduction. The share of ohmic voltage drop reduction (
iΔ
R
G
) in cell voltage reduction (Δ
U
G) was higher than 70% at all current densities. At constant cell voltage, the rate of hydrogen produced under super gravity field increased noticeably compared to that under normal gravity condition.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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