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As the production of electric vehicles and lithium-ion batteries continues to rise, concerns over resource scarcity and supply shortages of critical metals, including Cu, Ni, Co, Mn, and Li, have become increasingly urgent. To address these concerns and promote environmental protection, there is a growing demand for the recycling of hazardous waste containing these critical metals as secondary resources. Therefore, this paper proposes a novel synergistic solvent extraction system of D2EHPA-NNPA, which fills a gap in the lack of a suitable extraction system for the hydrometallurgical industry of secondary resources containing Cu, Ni, Co, Mn, and Li. With the specific extraction sequence of D2EHPA-NNPA, a novel process has been designed and proposed for the stepwise extraction of Cu, Ni, Co, Mn, and Li from secondary resources, which significantly simplifies process flows while avoiding cross-contamination of the extractants and the production of industrial wastewater. Furthermore, the proposed "extraction-scrubbing-stripping" process has been investigated from both macroscopic and microscopic perspectives, demonstrating that the novel synergistic solvent extraction system of D2EHPA-NNPA is a viable option for industrial applications to promote a circular economy and achieve sustainability objectives. [ABSTRACT FROM AUTHOR]

Electrocatalytic overall water splitting is a sustainable method to produce renewable hydrogen energy, but its industrial-scale application is limited by the high energy consumption caused by the high overpotential. Herein, we report the first example of constructing bifunctional cobalt/nitrogen-codoped carbon (CoNC) nanosheet arrays on copper foam (CF) to drive an energy-saving H2 production system with glucose-assisted Cu(I)/Cu(II) redox-looping. A series of size-controllable CoNC nanosheet arrays derived from a ZIF-L precursor are assembled on CF to balance the activity and durability of glucose-assisted Cu(I)/Cu(II) redox-looping and the HER. The optimized CoNC arrays can not only act as a highly-active electrocatalyst of the HER with outstanding electrochemical activity (η10 = 64 mV), but also protect the copper sites of CF from leaching in the glucose-assisted Cu(I)/Cu(II) redox-looping, thus significantly improving the stability of this self-supported electrode. Consequently, a superior energy-saving glucose-assisted system can be assembled by using this bifunctional Cu/CoNC as both the cathode and anode, which exhibits an ultra-low input cell voltage of 0.9 V to achieve 100 mA cm−2 with an ultra-low electricity consumption of 1.97 kW h per cubic meter of H2, much lower than the theoretical value of conventional overall water splitting (1.23 V and 2.7 kW h). [ABSTRACT FROM AUTHOR]