Construction of 3D hollow NiCo-layered double hydroxide nanostructures for high-performance industrial overall seawater electrolysis

Green hydrogen production via seawater electrolysis holds a great promise for carbon-neutral energy production. However, the development of efficient and low-cost bifunctional electrocatalysts for seawater electrolysis at an industrial level remains a significant challenge. Herein, we report a facile approach based on one-dimensional (1D) cobalt carbonate hydroxide (CCH) nanoneedles (NNs) as skeleton and zeolitic imidazolate framework-67 (ZIF-67) as a sacrificial template to construct a self-supported NiCo layered double hydroxide (NiCo LDH) heterostructure nanocage (CCH@NiCo LDH) anchoring on the carbon felt (CF). The NiCo LDHs have hollow features, consisting of ultrathin layered hydroxide nanosheets. Benefiting from the structural advantages, unique carbon substrate and desirable composition, three-dimensional (3D) NiCo LDH nanocages exhibit superior performance as a bifunctional catalyst for overall seawater splitting at an industrial level and good corrosion resistance in alkaline media. In the alkaline seawater (1 M KOH + 0.5 M NaCl), it exhibits low overpotentials of 356 mV for hydrogen evolution reaction (HER) and 433 mV for oxygen evolution reaction (OER) at 400 mA·cm^(−2), much better than most of reported non-noble metal catalysts. Consequently, the obtained CF electrode loading of CCH@NiCo LDH exhibits outstanding performance as anodes and cathodes for overall alkaline seawater splitting, with remarkably low cell voltages of 1.56 and 1.89 V at current densities of 10 and 400 mA·cm^(−2), respectively. Moreover, the robust stability of 100 h is also demonstrated at above 200 mA·cm^(−2) in alkaline seawater. Our present work demonstrates significant potential for constructing effective cost-efficient and non-noble-metal bifunctional electrocatalyst and electrode for industrial seawater splitting.

Interface engineering of 2D NiFe LDH/NiFeS heterostructure for highly efficient 5-hydroxymethylfurfural electrooxidation

The electrochemical oxidation of 5-hydroxymethylfurfural(HMF)to valuable chemicals is an efficient way to upgrade biomass molecules and replace traditional catalytic synthesis.It is crucial to develop efficient and low-cost earth-abundant electrocatalysts to enhance catalytic performance of HMF oxidation.Herein,a new type of two-dimensional(2D)hybrid arrays consisting of Ni Fe layered double hydroxides(LDH)nanosheets and bimetallic sulfide(Ni Fe S)is constructed via interface engineering for efficient electrocatalytic oxidation of HMF to 2,5-furandicarboxylic acid(FDCA).The preparation process of 2D Ni Fe LDH/NiFeS with ultrathin heterostructure involves in anchoring a Co-based metal-organic framework(Co MOF)as template onto the carbon cloth(CC)via in-situ growth,formation of NiFe LDH on the surface of Co MOF and subsequent partial sulfidation.The electrocatalyst of Ni Fe LDH/Ni Fe S exhibits outstanding performance towards HMF oxidation,about 98.5%yield for FDCA and 97.2%Faraday efficiency(FE)in the alkaline electrolyte with 10 mmol/L HMF,as well as excellent stability retaining 90.1%FE for FDCA after six cycles test.Moreover,even at an HMF concentration of 100 mmol/L,the yield and FE for FDCA remain high at 83.6%and 93.6%,respectively.These findings highlight that 2D heterostructure containing abundant interfaces between Ni Fe LDH nanosheets and Ni Fe S can enhance the intrinsic activity of LDH and thus promote the oxidation reaction kinetics.Additionally,the synergistic effect of the bimetallic Ni Fe compounds also improved the selectivity of HMF conversion to FDCA.Our present work demonstrates that constructing 2D ultrathin heterostructure of Ni Fe LDH/Ni Fe S is a facile strategy via interface engineering to enhance the intrinsic activity of LDH electrocatalysts,which would open new avenues toward low-cost and advanced 2D nanocatalysts for sustainable energy conversion and electrochemical valorization of biomass derivatives.

Highly efficient luminescent Ⅰ-Ⅲ-Ⅵ semiconductor nanoprobes based on template-synthesized CuInS2 nanocrystals

CuInS2 semiconductor nanocrystals (NCs) exhibit large absorption coefficient, size-dependent photoluminescence and low toxicity, making them excellent candidates in a variety of bioapplications. However, precise control of both their composition and morphology to improve the luminescent efficiency remains a great challenge via conventional direct synthesis. Herein, we present a novel low-temperature template synthesis of highly efficient luminescent CuInS2 nanoprobes from In2S3 NCs via a facile cation exchange strategy. The proposed strategy enables synthesis of a series of CuInS2 NCs with broad size tunability from 2.2 to 29.6 nm. Through rationally manipulating the stoichiometry of Cu/In, highly efficient luminescence of CuInS2 with the maximum quantum yield of 28.6% has been achieved, which is about one order of magnitude improvement relative to that of directly synthesized NCs. By virtue of the intense emission of CuInS2 nanoprobes, we exemplify their application in sensitive homogeneous biodetection for an important biomolecule of adenosine triphosphate (ATP) with the limit of detection down to 49.3 nM. Moreover, the CuInS2 nanoprobes are explored for ATP-targeted cancer cell imaging, thus revealing their great potentials in the field of cancer diagnosis and prognosis.

Emerging NIR-Ⅱ Luminescent Gold Nanoclusters for In Vivo Bioimaging

Gold nanoclusters(AuNCs)with near-infraredⅡ(NIR-Ⅱ)photoluminescence(PL)have emerged as novel bioimaging probes for in vivo disease diagnosis.So far,it still lacks a systematic review focusing on the synthesis,PL tuning,and in vivo imaging of NIR-Ⅱluminescent AuNCs.In this review,we briefly introduce the synthesis of NIR-Ⅱluminescent AuNCs using various surface ligands.We discuss the origins and properties of NIR-ⅡPL in AuNCs,and summarize the strategies for improving and/or tuning NIR-ⅡPL emissions.We also provide an overview of the recent progress in the application of AuNCs in tumor-targeted imaging,molecular imaging,and other areas(such as the sensitive imaging of bones,vessels,lymph nodes,etc.).Finally,we present the prospects and challenges in the field of NIR-Ⅱluminescent AuNCs and related imaging applications,expecting to offer comprehensive understanding of this field,and thereby deepening and broadening the biological application of AuNCs.

高效X射线紫外发光稀土纳米闪烁体及其活体X射线激活肿瘤治疗应用

基于X射线纳米闪烁体的光响应疗法是一种新兴的有良好应用前景的活体肿瘤治疗策略,迫切需要开发具有高效X射线激发紫外发光性能的纳米闪烁体.然而,由于当前纳米闪烁体的X射线紫外发光性能仍较弱,实现高效的X射线激活肿瘤治疗仍然是一个巨大的挑战.为此,我们发展了一种新型的具有良好X射线紫外发光性能的Gd^(3+)/Ce^(3+)共掺杂的LiLuF4纳米闪烁体,并将其应用于活体肿瘤治疗.通过优化基质材料、掺杂剂和能量传递设计合成的纳米闪烁体,其X射线紫外发光强度比传统的Ce^(3+)单掺杂材料增强了约18倍.我们进一步将纳米闪烁体与一氧化氮(NO)前体结合以概念验证研究纳米闪烁体的应用.在X射线照射下,该纳米复合物能够可控地产生NO,并在X射线诱导的NO和放射治疗协同作用下实现了优异的抗肿瘤效果.此外,X射线激活的NO治疗可以抑制肿瘤向肝脏转移,抑制肿瘤再生,延长小鼠存活率.这项工作有望推动纳米闪烁体的发展及其在活体深层组织疾病治疗中的应用.