Review of preferentially selective lithium extraction from spent lithium batteries: Principle and performance

Lithium,as the lightest and lowest potential metal,is an ideal "battery metal" and the core strategic metal of the new energy industry revolution.Recovering lithium from spent lithium batteries(LIBs)has become one of the significant approaches to obtaining lithium resources.At present,the lithium extraction being generally placed at the last step of the spent LIBs recovery process has puzzles such as high acid consumption,low Li recovery purity and low recovery efficiency.Selective lithium extraction at the first step of the recovery process can effectively solve those puzzles.Since lithium leaching is a non-spontaneous reaction requiring additional energy to achieve,it is found that these methods can be divided into five ways according to the different types of energy driving the reaction occurring:(ⅰ)electric energy driving lithium extraction;(ⅱ) chemical energy driving lithium extraction;(ⅲ) mechanical energy driving lithium extraction;(ⅳ) thermal energy driving lithium extraction;(ⅴ) other energy driving lithium extraction.Through the analysis of the principle,reaction process and results of recovering lithium methods can provide a few directions for scholars’ subsequent research.It is necessary to speed up the exploration of the principle of these methods.It is expected that this study could provide a reference for the research on the selective lithium extraction.

Feasible fabrication of o-phenanthroline-based polymer adsorbent for selective capture of aqueous Ag(Ⅰ)

Devising a desirable adsorbent for efficiently selective capture of Ag(Ⅰ) from wastewater has attracted much attention but faced with huge challenges. Herein, a novel linear o-phenanthroline-based polymer L-PRL was prepared via chemical oxidative polymerization for the adsorption of Ag(Ⅰ). The maximum adsorption capacity for Ag(Ⅰ) by L-PRL is 325.8 mg/g at pH 0. In addition, L-PRL owes ascendant selectivity for Ag(Ⅰ) from aqueous solutions containing various interfering metal ions of Pb(Ⅱ), Co(Ⅱ), Ni(Ⅱ), Cd(Ⅱ)and Fe(Ⅲ). Multiple characterizations of FT-IR and XPS uncover that the N groups on L-PRL act as adsorption sites to coordinate with Ag(Ⅰ). Density functional theory(DFT) calculations further evidence the mechanism that L-PRL is provided with the admirable adsorptivity and selectivity for Ag(Ⅰ). It is mainly attributed to the most stable complexes of L-PRL with Ag(Ⅰ), which possesses shortest Ag-N bond length compared with other heavy metal ions. Furthermore, 93.5% of initial adsorption capacity is reserved after four continuous regeneration cycles, indicating that L-PRL is equipped with superior recyclability and durability, and L-PRL is capable of removing Ag(Ⅰ) in low-concentration actual Ag(Ⅰ)-containing wastewater completely. This study shed light on the rational design of polymer adsorbents and in-depth insight into selective removal of aqueous Ag(Ⅰ).

A pyrazine based metal-organic framework for selective removal of copper from strongly acidic solutions

The selective capture of copper from strongly acidic solutions is of vital importance from the perspective of sustainable development and environmental protection.Metal organic frameworks(MOFs)have attracted the interest of many scholars for adsorption due to their fascinating physicochemical characteristics,including adjustable structure,strong stability and porosity.Herein,pz-UiO-66 containing a pyrazine structure is successfully synthesized for the efficient separation of copper from strongly acidic conditions.Selective copper removal at low pH values is accomplished by using this material that is not available in previously reported metal–organic frameworks.Furthermore,the material exhibits excellent adsorption capacity,with a theoretical maximum copper uptake of 247 mg/g.As proven by XPS and FT-IR analysis,the coordination of pyrazine nitrogen atoms with copper ions is the dominant adsorption mechanism of copper by pz-UiO-66.This work provides an opportunity for efficient and selective copper removal under strongly acidic conditions,and promises extensive application prospects for the removal of copper in the treatment for acid metallurgical wastewater.

Lattice expansion boosting photocatalytic degradation performance of CuCo_(2)S_(4) with an inherent dipole moment

Realizing efficient charge separation and directional transfer is a challenge for single-component semiconductors.The spatial electric field generated by dipole moment could promote charge separation.Here,three-dimensional hierarchical Cu Co_(2)S_(4)microspheres with lattice distortion were prepared,and lattice distortion was modulated by changing feed Co/Cu molar ratios in synthesis.Cu Co_(2)S_(4)showed asymmetric crystal structure,leading to generation of dipole moment.The charge separation efficiency of Cu Co_(2)S_(4)was related to lattice distortion,and lattice expansion was in favor for charge separation.The Cu Co_(2)S_(4)with feed Cu/Co molar ratio of 1:4 (CCS-4) showed the maximum lattice expansion and exhibited the highest photocatalytic activity,which was attributable to the highest charge separation efficiency and the largest specific surface area.CCS-4 can remove 95.4%of tetracycline hydrochloride within 40 min photocatalysis,and effectively improve the biodegradability of pharmaceutical wastewater.Importantly,this study provides a new vision for constructing single-component photocatalysts with high photocatalytic performance.

Metal-center effect induced efficient charge transfer of metal-organic framework for strengthening Sb(Ⅴ)capture performance

The adsorbents–adsorbates interaction is critical for resourcelization in heavy metal wastewater treatment.Nevertheless,it is still indistinct to depict the impact of metal center effect on heavy metals removal performance in metal-organic frameworks(MOFs)-based adsorbents.Herein,a series of MOFs with different metal centers of Mg(II),La(III),and Zr(IV)are rationally designed,and the effect of electronic structure on the Sb(V)removal performance is systematically investigated.The obtained La-MGs achieve Sb(V)adsorption capacity of 897.6 mg/g,which is about 1.2 and 4.5 times above average than those of Zr-MGs and Mg-MGs,respectively.On account of more edge adsorption sites achieve,the sites utilization efficiency of La-MGs(92.1%)is much better than Zr-MGs(75.0%)and Mg-MGs(20.4%).Furthermore,density functional theory(DFT)calculations reveal that La-MGs are more active than Mg-MGs and Zr-MGs,owing to the lower adsorption energy,higher charge transfer,and stronger bonding interaction,which will promote the Sb(V)removal performance.The experimental results in practical water indicate that La-MGs effectively capture antimony at low concentration,reaching drinking water standard in samples from Ganjiang River.This study opens an avenue for atomic-level insight into high-efficient absorbents design for water treatment from electronic structuremodification of active centers.