Supercapacitors are regarded to be highly probable candidates for next-generation energy storage devices. Herein, a bimetallic Co/Ni MOF is used as a sacrificial template through an alkaline hydrolysis and selective oxidation process to prepare an accordion-like ternary NiCoO/β-Ni Co(OH)/α-Ni Co(OH) composite, which is composed of Co/Ni(OH) nanosheets with large specific surface as the frame and NiCoO nanoparticles with high conductivity as the insertion, for supercapacitor application. This material exhibits both high specific capacitance (1315 F·g at 5 A·g) and excellent cycle performance (retained 90.7% after 10 000 cycles). This hydrolysis-oxidation process, alkali hydrolysis followed by oxidation with HO, offers a novel approach to fabricate the Ni/Co-based electrode materials with enhanced supercapacitor performance.
This scoping review analyzes the research gaps of three diseases: schistosomiasis japonica, malaria and echinococcosis. Based on available data in the P.R. China, we highlight the gaps between control capacity and prevalence levels, and between diagnostic/drug development and population need for treatment at different stages of the national control programme. After reviewing the literature from 848 original studies and consultations with experts in the field, the gaps were identified as follows. Firstly, the malaria research gaps include (i) deficiency of active testing in the public community and no appropriate technique to evaluate elimination, (ii) lack of sensitive diagnostic tools for asymptomatic patients, (iii) lack of safe drugs for mass administration. Secondly, gaps in research of schistosomiasis include (i) incongruent policy in the implementation of integrated control strategy for schistosomiasis, (ii) lack of effective tools for Oncomelania sp. snail control, (iii) lack of a more sensitive and cheaper diagnostic test for large population samples, (iv) lack of new drugs in addition to praziquantel. Thirdly, gaps in research of echinococcosis include (i) low capacity in field epidemiology studies, (ii) lack of sanitation improvement studies in epidemic areas, (iii) lack of a sensitivity test for early diagnosis, (iv) lack of more effective drugs for short-term treatment. We believe these three diseases can eventually be eliminated in mainland China if all the research gaps are abridged in a short period of time.
Nickel/cobalt hydroxide is a promising battery‐type electrode material for supercapacitors. However, its low cycle stability hinders further applications. Herein, Ni0.7Co0.3(OH)2 core–shell microspheres exhibiting extreme‐prolonged cycling life are successfully synthesized, employing Ni‐Co‐metal–organic framework (MOF) as the precursor/template and a specific hydrolysis strategy. The Ni‐Co‐MOF and KOH aqueous solution are separated and heated to 120 °C before mixing, rather than mixing before heating. Through this hydrolysis strategy, no MOF residual exists in the product, contributing to close stacking of the hydroxide nanoflakes to generate Ni0.7Co0.3(OH)2 microspheres with a robust core–shell structure. The electrode material exhibits high specific capacity (945 C g−1 at 0.5 A g−1) and unprecedented cycling performance (100% after 10 000 cycles). The fabricated asymmetric supercapacitor delivers an energy density of 40.14 Wh kg−1 at a power density of 400.56 W kg−1 and excellent cycling stability (100% after 20 000 cycles). As far as is known, it is the best cycling performance for pure Ni/Co(OH)2.
HIGHLIGHTS • A facile and effective epitaxial-like growth strategy is applied to fabricate the NiSe 2 /Ni(OH) 2 heterojunction composite. • The assembled asymmetric supercapacitor based on the heterojunction composite surpasses most of the reported results. It is the first time that the powdered electrode materials can have such large capacity, high rate, and extreme long cycle life.
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