Enhancing the stability of Ni Fe-layered double hydroxide nanosheet array for alkaline seawater oxidation by Ce doping

Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution.

Antibiotic-based small molecular micelles combined with photodynamic therapy for bacterial infections

The appearance of multidrug-resistant bacteria and the formation of bacterial biofilms have necessitated the development of alternative antimicrobial therapeutics.Antibiotics conjugated with or embedded in nano-drug carriers show a great potential and advantage over free drugs,but the mass proportion of carriers generally exceeds 90%of the nano-drug,resulting in low drug loading and limited therapeutic output.Herein,we fabricated a nanocarrier using antibiotics as the building blocks,minimizing the use of carriermaterials,significantly increasing the drug loading content and treatment effect.Firstly,we conjugated betaine carboxylate with ciprofloxacin(CIP)through an ester bond to form the amphiphilic conjugate(CIP-CB),which self-assembled into micelles(CIP-CBMs)in aqueous solutions,with a CIP loading content as high as 65.4%and pH-induced surface charge reversal properties.Secondly,a model photosensitizer(5,10,15,20-tetraphenylporphyrin(TPP))was encapsulated in CIP-CBMs,generating infection-targeted photodynamic/antibiotic combined nanomedicines(denoted as TPP@CIP-CBMs).Upon accumulation at infection sites or in deep bacterial biofilms,the ester bond between the betaine carboxylate and CIP is cleaved to release free TPP and CIP,leading to a synergetic antibacterial and antibiofilm activity in vitro and in vivo.

Surface-derived phosphate layer on NiFe-layered double hydroxide realizes stable seawater oxidation at the current density of 1 A·cm^(−2)

Seawater electrolysis,especially in coastlines,is widely considered as a sustainable way of making clean and high-purity H2 from renewable energy;however,the practical viability is challenged severely by the limited anode durability resulting from side reactions of chlorine species.Herein,we report an effective Cl^(−) blocking barrier of NiFe-layer double hydroxide(NiFe-LDH)to harmful chlorine chemistry during alkaline seawater oxidation(ASO),a pre-formed surface-derived NiFe-phosphate(Pi)outerlayer.Specifically,the PO_(4)^(3−)-enriched outer-layer is capable of physically and electrostatically inhibiting Cl−adsorption,which protects active Ni^(3+)sites during ASO.The NiFe-LDH with the NiFe-Pi outer-layer(NiFe-LDH@NiFe-Pi)exhibits higher current densities(j)and lower overpotentials to afford 1 A·cm^(−2)(η1000 of 370 mV versusη1000 of 420 mV)than the NiFe-LDH in 1 M KOH+seawater.Notably,the NiFe-LDH@NiFe-Pi also demonstrates longer-term electrochemical durability than NiFe-LDH,attaining 100-h duration at the j of 1 A·cm^(−2).Additionally,the importance of surface-derived PO_(4)^(3−)-enriched outer-layer in protecting the active centers,γ-NiOOH,is explained by ex situ characterizations and in situ electrochemical spectroscopic studies.

Electrocatalytic synthesis of C-N coupling compounds from CO_(2) and nitrogenous species

The electrocatalytic synthesis of C-N coupling compounds from CO_(2) and nitrogenous species not only offers an effective avenue to achieve carbon neutral-ity and reduce environmental pollution,but also establishes a route to synthesize valuable chemicals,such as urea,amide,and amine.This innovative approach expands the application range and product categories beyond simple carbona-ceous species in electrocatalytic CO_(2) reduction,which is becoming a rapidly advancing field.This review summarizes the research progress in electrocatalytic urea synthesis,using N_(2),NO_(2)^(-),and NO_(3)^(-)as nitrogenous species,and explores emerging trends in the electrosynthesis of amide and amine from CO_(2) and nitro-gen species.Additionally,the future opportunities in this field are highlighted,including electrosynthesis of amino acids and other compounds containing C-N bonds,anodic C-N coupling reactions beyond water oxidation,and the catalytic mechanism of corresponding reactions.This critical review also captures the insights aimed at accelerating the development of electrochemical C-N coupling reactions,confirming the superiority of this electrochemical method over the traditional techniques.

Ambient electrosynthesis of urea from carbon dioxide and nitrate over Mo_(2)C nanosheet

Electrocatalytic synthesis of urea through C-N bond formation,converting carbon dioxide(CO_(2))and ni-trate(NO_(3)^(-)),presents a promising,less energy-intensive alternative to industrial urea production process.In this communication,we report the application of Mo_(2)C nanosheets-decorated carbon sheets(Mo_(2)C/C)as a highly efficient electrocatalyst for facilitating C-N coupling in ambient urea electrosynthesis.In CO_(2)-saturated 0.2 mol/L Na_(2)SO_(4)solution containing 0.05 mol/L NO_(3)^(-),the Mo_(2)C/C catalyst achieves an impres-sive urea yield of 579.13μg h^(-1)mg^(-1)with high Faradaic efficiency of 44.80%at-0.5 V versus the reversible hydrogen electrode.Further theoretical calculations reveal that the multiple Mo active sites enhance the formation of^(∗)CO and^(∗)NH_(2)intermediates and facilitate their C-N coupling.This research propels the use of Mo_(2)C-based electrodes in electrocatalysis and accentuates the capabilities of binary metal-based catalysts in C-N coupling reactions.

Cauliflower-like Ni_(3)S_(2) foam for ultrastable oxygen evolution electrocatalysis in alkaline seawater

It is of great importance to design and develop electrocatalysts that are both long-lasting and efficient for seawater oxidation.Herein,a three-dimensional porous cauliflower-like Ni_(3)S_(2) foam on Ni foam(Ni_(3)S_(2) foam/NF)is proposed as a high-performance electrocatalyst for the oxygen evolution reaction in alkaline seawater.The as-synthesis Ni_(3)S_(2) foam/NF achieves exceptional efficacy,achieving a current density of 100 mA·cm^(−2)at mere overpotential of 369 mV.Notably,its electrocatalytic stability extends up to 1000 h at 500 mA·cm^(−2).

Targeted genome engineering in human induced pluripotent stem cells by penetrating TALENs

Background:Zinc-finger nucleases(ZFNs)and transcription activator-like effector nucleases(TALENs)have been successfully used to knock out endogenous genes in stem cell research.However,the deficiencies of current gene-based delivery systems may hamper the clinical application of these nucleases.A new delivery method that can improve the utility of these nucleases is needed.Results:In this study,we utilized a cell-penetrating peptide-based system for ZFN and TALEN delivery.Functional TAT-ZFN and TAT-TALEN proteins were generated by fusing the cell-penetrating TAT peptide to ZFN and TALEN,respectively.However,TAT-ZFN was difficult to purify in quantities sufficient for analysis in cell culture.Purified TAT-TALEN was able to penetrate cells and disrupt the gene encoding endogenous human chemokine(C-C motif)receptor 5(CCR5,a co-receptor for HIV-1 entry into cells).Hypothermic treatment greatly enhanced the TAT-TALENmediated gene disruption efficiency.A 5%modification rate was observed in human induced pluripotent stem cells(hiPSCs)treated with TAT-TALEN as measured by the Surveyor assay.Conclusions:TAT-TALEN protein-mediated gene disruption was applicable in hiPSCs and represents a promising technique for gene knockout in stem cells.This new technique may advance the clinical application of TALEN technology.

CoSe_(2)nanowire array enabled highly efficient electrocatalytic reduction of nitrate for ammonia synthesis

The electrocatalytic reduction of nitrate(NO_(3)^(-))not only facilitates the environmentally sustainable production of ammonia(NH_(3))but also purifies water by removing NO_(3)^(-),thereby transforming waste into valuable resources.The process of converting NO_(3)^(-)to NH_(3)is complex,involving eight electron transfers and multiple intermediates,making the choice of electrocatalyst critical.In this study,we report a cobalt selenide(Co Se_(2))nanowire array on carbon cloth(CoSe_(2)/CC)as an effective electrocatalyst for the NO_(3)^(-)to NH_(3)conversion.In an alkaline medium with 0.1 mol/L NO_(3)^(-),CoSe_(2)/CC demonstrates exceptional NH_(3)Faradaic efficiency of 97.6%and a high NH_(3)yield of 517.7μmol h^(-1)cm^(-2)at-0.6 V versus the reversible hydrogen electrode.Furthermore,insights into the reaction mechanism of CoSe_(2)in the electrocatalytic NO_(3)^(-)reduction are elucidated through density functional theory calculations.