Rational Design of Titanium Carbide MXene Electrode Architectures for Hybrid Capacitive Deionization

Intercalation redox materials have shown great promise for efficient water desalination due to available faradaic gallery sites.Symmetric capacitive deionization(CDI)cells previously demonstrated using MXenes were often limited in their salt adsorption capacity(SAC)and voltage window of operation.In this study,current collector-and binder-free Ti3C2Tx MXene electrode architectures are designed with porous carbon as the positive electrode to demonstrate hybrid CDI(HCDI)operation.Furthermore,MXene current collectors are fabricated by employing a scalable doctor blade coating technique and subsequently spray coating a layer of a small flake MXene dispersion.Hydrophilic redox-active galleries of MXenes are capable of intercalating a variety of aqueous cations including Na+,K+,and Mg2+ions,showing volumetric capacitances up to 250 F cm-3.As a result,a salt removal capacity of 39 mg g-1 with decent cycling stability is achieved.This study opens new avenues for developing freestanding,binder-and additivefree MXene electrodes for HCDI applications.

Human embryonic stem cell lines with ccr5-del32 allele conferring resistance to HIV

A 32bp deletion in the chemokine receptor 5 (CCR5) gene (CMKBR5) was shown to be linked to HIV resistance. Bone marrow transplantation from the homozygous CCR5-del32 donor to a CDC Stage 2 HIV-positive recipient was demonstrated to confer a HIV resistance, resulting in discontinuation of antiretroviral therapy. In search for an unlimited source of CCR5-del32 cells for transplantation purposes, we tested 137 human embryonic stem cell (hESC) lines from the Reproductive Genetics Institute’s hESC lines collection, and report here the finding of 12 hESC lines with the CCR5-del32 allele, one of which represents a unique partenogenetic ESC line containing two copies of this deletion and may be studied for utility in stem cell transplantation treatment of HIV.

Free-Standing α-MoO_(3)/Ti_(3)C_(2) MXene Hybrid Electrode in Water-in-Salt Electrolytes

While transition-metal oxides such as α-MoO_(3)provide high capacity,their use is limited by modest electronic conductivity and electrochemical instability in aqueous electrolytes.Two-dimensional(2D)MXenes,offer metallic conductivity,but their capacitance is limited in aqueous electrolytes.Insertion of partially solvated cations into Ti_(3)C_(2)MXene from lithium-based water-in-salt(WIS)electrolytes enables charge storage at positive potentials,allowing a wider potential window and higher capacitance.Herein,we demonstrate that α-MoO_(3)/Ti_(3)C_(2)hybrids combine the high capacity of α-MoO_(3)and conductivity of Ti_(3)C_(2)in WIS(19.8 m LiCI)electrolyte in a wide1.8 V voltage window.Cyclic voltammograms reveal multiple redox peaks from α-MoO_(3)in addition to the well-separated peaks of Ti_(3)C_(2)in the hybrid electrode.This leads to a higher specific charge and a higher rate capability compared to a carbon and binder containing α-MoO_(3)electrode.These results demonstrate that the addition of MXene to less conductive oxides eliminates the need for conductive carbon additives and binders,leads to a larger amount of charge stored,and increases redox capacity at higher rates.In addition,MXene encapsulated α-MoO_(3)showed improved electrochemical stability,which was attributed to the suppressed dissolution of α-MoO_(3).The work suggests that oxide/MXene hybrids are promising for energy storage.