Surpassing electrocatalytic limit of earth-abundant Fe^(4+)embedded in N-doped graphene for(photo)electrocatalytic water oxidation

Developing highly active,cost-effective,and environmental friendly oxygen evolution reaction(OER)electrocatalysts facilitates various(photo)electrochemical processes.In this work,Fe3N nanoparticles encapsulated into N-doped graphene nanoshells(Fe_(3)N@NG)as OER electrocatalysts in alkaline media were reported.Both the experimental and theoretical comparison between Fe_(3) N@NG and Fe_(3)N/NG,specifically including in situ Mossbauer analyses,demonstrated that the NG nanoshells improved interfacial electron transfer process from Fe_(3)N to NG to form high-valence Fe^(4+)ions(Fe^(4+)@NG),thus modifying electronic properties of the outer NG shells and subsequently electron transfer from oxygen intermediate to NG nanoshells for OER catalytic process.Meanwhile,the NG nanoshells also protected Fe-based cores from forming OER inactive and insulated Fe_(2)O_(3),leading to high OER stability.As a result,the as-formed Fe^(4+)@NG shows one of the highest electrocatalytic efficiency among reported Fe-based OER electrocatalysts,which can as well highly improve the photoelectrochemical water oxidation when used as the cocatalysts for the Fe_(2)O_(3) nanoarray photoanode.

Influence of charge transport layer on the crystallinity and charge extraction of pure tin-based halide perovskite film

As one of the most compelling photovoltaic devices, halide perovskite (PVK) solar cells have achieved a new surprising record power conversion efficiency (PCE) of 25.8%in 2021 [1]. This demonstrates the great potential of halide PVK solar cells as a highly competitive substitute to replace silicon-based solar cells in the photovoltaic market [2–6].

Thiourea-assisted coating of dispersed copper electrocatalysts on Si photocathodes for solar hydrogen production

Photoelectrochemical water splitting can convert solar energy into clean hydrogen energy for storage.It is desirable to explore non-precious electrocatalysts for practical applications of a photoelectrode in a large scale.Here,we developed a facile spin-coating and in-situ photoelectrochemical reduction method to prepare a dispersed Cu electrocatalyst on a Si photocathode,which improves the performance remarkably.We find that thiourea in the precursor solution for spin-coating plays an important role in obtaining dispersed Cu particles on the surface of a Si photoelectrode.With thiourea in the precursor,the Cu/Si photocathode shows higher performance than the one without thiourea.Moreover,the Cu/Si photocathode also indicates good stability after 16 h illumination.

Super stable CsPbBr3@SiO2 tumor imaging reagent by stress-response encapsulation

Great photoelectric properties can herald the high potentials of CsPbBr3 nanocrystals(NCs)to function as the fluorescent probes for early tumor diagnosis.However,the intrinsic water vulnerability of CsPbBr3 NCs highly restricts their biomedical applications.To conquer this challenge,we herein introduce a nature inspired"stress-response"method to tightly encapsulate CsPbBr3 into SiO2 nano-shells that can dramatically improve the water stability of CsPbBr3@SiO2 nanoparticles for over 48 h.We further highlighted the advantageous features of CsPbBr3@SiO2 by using them as the fluorescent probes for CT26 tumor cell imaging with their high water stability,biocompatibility,and low cytotoxicity.Our work for the first time exhibited the potential of lead halide perovskite NCs for tumor diagnosis,and can highly anticipate the further in vivo biomedical applications that light up live cells.

An Extrinsic Faradaic Layer on CuSn for High-Performance Electrocatalytic CO_(2) Reduction

An intrinsic Faradaic layer on the surface of a metal electrocatalyst is usually considered an active site for CO_(2) reduction.Different strategies have been used to improve the performance of CO_(2) reduction by adjusting the intrinsic Faradaic layer.However,it is still challenging to achieve CO_(2) reduction with high activity,selectivity,and stability.In this study,for the first time,we improve the three parameters simultaneously by introducing a Zn(OH)_(x) over layer onto a CuSn electrocatalyst.We find that the intrinsic Faradaic layer of Sn(OH)_(x) on the surface of CuSn provides active sites for CO_(2) reduction,while Zn(OH)_(x) plays multiple roles as an adsorption/activation layer,a cover layer,and a protective layer.Further studies suggest that the enhanced activity comes from a Faradaic reaction of Zn(OH)_(x) during CO_(2) reduction,which can be considered as an extrinsic Faradaic layer.This new strategy of introducing an extrinsic Faradaic layer can deepen understanding of electrocatalytic process and offers guidance to design other high-performance electrocatalysts.

Photosynthetic microorganisms coupled photodynamic therapy for enhanced antitumor immune effect

The ideal photodynamic therapy(PDT)should effectively remove the primary tumor,and produce a stronger immune memory effect to inhibit the tumor recurrence and tumor metastasis.However,limited by the hypoxic and immunosuppressive microenvironment,the PDT efficiency is apparently low.Here,Chlorella(Chl.)is exploited to enhance local effect by producing oxygen to reverse hypoxia,and release adjuvants to reverse immunosuppressive microenvironment to enhance abscopal effect afterwards.Results from different animal models indicated that Chl.could enhance local effect and PDT related immune response.Ultimately,Chl.coupled PDT elicited anti-tumor effects toward established primary tumors(inhibition rate:90%)and abscopal tumors(75%),controlled the challenged tumors(100%)and alleviated metastatic tumors(90%).This Chl.coupled PDT strategy can also produce a stronger anti-tumor immune memory effect.Overall,this Chl.coupled PDT strategy generates enhanced local tumor killing,boosts PDT-induced immune responses and promotes anti-tumor immune memory effect,which may be a great progress for realizing systemic effect of PDT.