Hefei Institutes of Physical Science

autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field.

reduction, etc.) and photothermal catalysis play key roles in solar to chemical/thermal energy conversion via the light-matter interaction. The major challenges in traditional semiconductor photocatalysts include insufficient sunlight utilization, charge carrier recombination, limited exposure of active sites, and particularly the difficulty of understanding the structure-activity relationship. Metal-organic frameworks (MOFs), featuring semiconductor-like behavior, have recently captured broad interest toward photocatalysis and photothermal catalysis because of their well-defined and tailorable porous structures, high surface areas, etc. These advantages are beneficial for rational structural modulation for improved light harvesting and charge separation as well as other effects, greatly helping to address the aforementioned challenges and especially facilitating the establishment of the structure-activity relationship. Therefore, it is increasingly important to summarize this research field and provide in-depth insight into MOF-based photocatalysis and photothermal catalysis to accelerate the future development. In this Account, we have summarized the recent advances in these two directly relevant applications, photocatalysis and photothermal catalysis, mainly focusing on the results in our lab. Given the unique structural features of MOFs, we have put an emphasis on rational material design to optimize the components and performance and to understand related mechanisms behind the enhanced activity. This Account starts by presenting an overview of solar energy conversion by catalysis. We explain why MOFs can be promising photocatalysts and exemplify the semiconductor-like behavior of MOFs. More importantly, we show that MOFs provide a powerful platform to study photocatalysis, in which the involved three key processes, namely, light harvesting, electron-hole separation, and surface redox reactions, can be rationally improved. Meanwhile, the structure-activity relationship and charge separation dynamics are illustrated in this part. In addition, MOFs for photothermal catalysis have been introduced that are based on the photothermal effect of plasmonic metals and/or MOFs, together with light-driven electronic state optimization of active sites, toward enhanced heterogeneous organic reactions. Finally, our brief outlooks on the current challenges and future development of MOF photocatalysis and photothermal catalysis are provided. It is believed that this Account will afford significant understanding and inspirations toward solar energy conversion over MOF-based catalysts.

Clearing senescent cells extends healthspan in mice. Using a hypothesis-driven bioinformatics-based approach, we recently identified pro-survival pathways in human senescent cells that contribute to their resistance to apoptosis. This led to identification of dasatinib (D) and quercetin (Q) as senolytics, agents that target some of these pathways and induce apoptosis preferentially in senescent cells. Among other pro-survival regulators identified was Bcl-xl. Here, we tested whether the Bcl-2 family inhibitors, navitoclax (N) and TW-37 (T), are senolytic. Like D and Q, N is senolytic in some, but not all types of senescent cells: N reduced viability of senescent human umbilical vein epithelial cells (HUVECs), IMR90 human lung fibroblasts, and murine embryonic fibroblasts (MEFs), but not human primary preadipocytes, consistent with our previous finding that Bcl-xl siRNA is senolytic in HUVECs, but not preadipocytes. In contrast, T had little senolytic activity. N targets Bcl-2, Bcl-xl, and Bcl-w, while T targets Bcl-2, Bcl-xl, and Mcl-1. The combination of Bcl-2, Bcl-xl, and Bcl-w siRNAs was senolytic in HUVECs and IMR90 cells, while combination of Bcl-2, Bcl-xl, and Mcl-1 siRNAs was not. Susceptibility to N correlated with patterns of Bcl-2 family member proteins in different types of human senescent cells, as has been found in predicting response of cancers to N. Thus, N is senolytic and acts in a potentially predictable cell type-restricted manner. The hypothesis-driven, bioinformatics-based approach we used to discover that dasatinib (D) and quercetin (Q) are senolytic can be extended to increase the repertoire of senolytic drugs, including additional cell type-specific senolytic agents.

Although biomimetic designs are expected to play a key role in exploring future structural materials, facile fabrication of bulk biomimetic materials under ambient conditions remains a major challenge. Here, we describe a mesoscale "assembly-and-mineralization" approach inspired by the natural process in mollusks to fabricate bulk synthetic nacre that highly resembles both the chemical composition and the hierarchical structure of natural nacre. The millimeter-thick synthetic nacre consists of alternating organic layers and aragonite platelet layers (91 weight percent) and exhibits good ultimate strength and fracture toughness. This predesigned matrix-directed mineralization method represents a rational strategy for the preparation of robust composite materials with hierarchically ordered structures, where various constituents are adaptable, including brittle and heat-labile materials.

Prussian blue analogue (PBA)-derived carbon coated porous nickel phosphides nanoplates exhibit enhanced electrocatalytic activity for oxygen evolution reaction.

Monitoring open water bodies accurately is an important and basic application in remote sensing. Various water body mapping approaches have been developed to extract water bodies from multispectral images. The method based on the spectral water index, especially the Modified Normalized Difference Water Index (MDNWI) calculated from the green and Shortwave-Infrared (SWIR) bands, is one of the most popular methods. The recently launched Sentinel-2 satellite can provide fine spatial resolution multispectral images. This new dataset is potentially of important significance for regional water bodies’ mapping, due to its free access and frequent revisit capabilities. It is noted that the green and SWIR bands of Sentinel-2 have different spatial resolutions of 10 m and 20 m, respectively. Straightforwardly, MNDWI can be produced from Sentinel-2 at the spatial resolution of 20 m, by upscaling the 10-m green band to 20 m correspondingly. This scheme, however, wastes the detailed information available at the 10-m resolution. In this paper, to take full advantage of the 10-m information provided by Sentinel-2 images, a novel 10-m spatial resolution MNDWI is produced from Sentinel-2 images by downscaling the 20-m resolution SWIR band to 10 m based on pan-sharpening. Four popular pan-sharpening algorithms, including Principle Component Analysis (PCA), Intensity Hue Saturation (IHS), High Pass Filter (HPF) and À Trous Wavelet Transform (ATWT), were applied in this study. The performance of the proposed method was assessed experimentally using a Sentinel-2 image located at the Venice coastland. In the experiment, six water indexes, including 10-m NDWI, 20-m MNDWI and 10-m MNDWI, produced by four pan-sharpening algorithms, were compared. Three levels of results, including the sharpened images, the produced MNDWI images and the finally mapped water bodies, were analysed quantitatively. The results showed that MNDWI can enhance water bodies and suppressbuilt-up features more efficiently than NDWI. Moreover, 10-m MNDWIs produced by all four pan-sharpening algorithms can represent more detailed spatial information of water bodies than 20-m MNDWI produced by the original image. Thus, MNDWIs at the 10-m resolution can extract more accurate water body maps than 10-m NDWI and 20-m MNDWI. In addition, although HPF can produce more accurate sharpened images and MNDWI images than the other three benchmark pan-sharpening algorithms, the ATWT algorithm leads to the best 10-m water bodies mapping results. This is no necessary positive connection between the accuracy of the sharpened MNDWI image and the map-level accuracy of the resultant water body maps.

Abstract The scalable production of hydrogen could conveniently be realized by alkaline water electrolysis. Currently, the major challenge confronting hydrogen evolution reaction (HER) is lacking inexpensive alternatives to platinum-based electrocatalysts. Here we report a high-efficient and stable electrocatalyst composed of ruthenium and cobalt bimetallic nanoalloy encapsulated in nitrogen-doped graphene layers. The catalysts display remarkable performance with low overpotentials of only 28 and 218 mV at 10 and 100 mA cm −2 , respectively, and excellent stability of 10,000 cycles. Ruthenium is the cheapest platinum-group metal and its amount in the catalyst is only 3.58 wt.%, showing the catalyst high activity at a very competitive price. Density functional theory calculations reveal that the introduction of ruthenium atoms into cobalt core can improve the efficiency of electron transfer from alloy core to graphene shell, beneficial for enhancing carbon–hydrogen bond, thereby lowing ΔG H* of HER.

Metal sulfide hollow nanostructures (MSHNs) have received intensive attention as electrode materials for electrical energy storage (EES) systems due to their unique structural features and rich chemistry. Here, we summarize recent research progress in the rational design and synthesis of various metal sulfide hollow micro‐/nanostructures with controlled shape, composition and structural complexity, and their applications to lithium ion batteries (LIBs) and hybrid supercapacitors (HSCs). The current understanding of hollow structure control, including single‐shelled, yolk‐shelled, multi‐shelled MSHNs, and their hybrid micro‐/nanostructures with carbon (amorphous carbon nanocoating, graphene and hollow carbon), is focused on. The importance of proper structural and compositional control on the enhanced electrochemical properties of MSHNs is emphasized. A relationship between structural and compositional engineering with improved electrochemical activity of MSHNs is sought, in order to shed some light on future electrode design trends for next‐generation EES technologies.

Abstract Perovskite solar cells with the formula FA 1− x Cs x PbI 3 , where FA is formamidinium, provide an attractive option for integrating high efficiency, durable stability and compatibility with scaled-up fabrication. Despite the incorporation of Cs cations, which could potentially enable a perfect perovskite lattice 1,2 , the compositional inhomogeneity caused by A-site cation segregation is likely to be detrimental to the photovoltaic performance of the solar cells 3,4 . Here we visualized the out-of-plane compositional inhomogeneity along the vertical direction across perovskite films and identified the underlying reasons for the inhomogeneity and its potential impact for devices. We devised a strategy using 1-(phenylsulfonyl)pyrrole to homogenize the distribution of cation composition in perovskite films. The resultant p–i–n devices yielded a certified steady-state photon-to-electron conversion efficiency of 25.2% and durable stability.

The heat shock proteins (HSPs) are ubiquitous and conserved protein families in both prokaryotic and eukaryotic organisms, and they maintain cellular proteostasis and protect cells from stresses. HSP protein families are classified based on their molecular weights, mainly including large HSPs, HSP90, HSP70, HSP60, HSP40, and small HSPs. They function as molecular chaperons in cells and work as an integrated network, participating in the folding of newly synthesized polypeptides, refolding metastable proteins, protein complex assembly, dissociating protein aggregate dissociation, and the degradation of misfolded proteins. In addition to their chaperone functions, they also play important roles in cell signaling transduction, cell cycle, and apoptosis regulation. Therefore, malfunction of HSPs is related with many diseases, including cancers, neurodegeneration, and other diseases. In this review, we describe the current understandings about the molecular mechanisms of the major HSP families including HSP90/HSP70/HSP60/HSP110 and small HSPs, how the HSPs keep the protein proteostasis and response to stresses, and we also discuss their roles in diseases and the recent exploration of HSP related therapy and diagnosis to modulate diseases. These research advances offer new prospects of HSPs as potential targets for therapeutic intervention.

Abstract Sodium‐ion batteries (SIBs) have a promising application prospect for energy storage systems due to the abundant resource. Amorphous carbon with high electronic conductivity and high surface area is likely to be the most promising anode material for SIBs. However, the rate capability of amorphous carbon in SIBs is still a big challenge because of the sluggish kinetics of Na + ions. Herein, a three‐dimensional amorphous carbon (3DAC) with controlled porous and disordered structures is synthesized via a facile NaCl template‐assisted method. Combination of open porous structures of 3DAC, the increased disordered structures can not only facilitate the diffusion of Na + ions but also enhance the reversible capacity of Na storage. When applied as anode materials for SIBs, 3DAC exhibits excellent rate capability (66 mA h g −1 at 9.6 A g −1 ) and high reversible capacity (280 mA h g −1 at a low current density of 0.03 A g −1 ). Moreover, the controlled porous structures by the NaCl template method provide an appropriate specific surface area, which contributes to a relatively high initial Coulombic efficiency of 75%. Additionally, the high‐rate 3DAC material is prepared via a green approach originating from low‐cost pitch and NaCl template, demonstrating an appealing development of carbon anode materials for SIBs.

Molybdenum disulfide (MoS2) has received considerable interest for electrochemical energy storage and conversion. In this work, we have designed and synthesized a unique hybrid hollow structure by growing ultrathin MoS2 nanosheets on N-doped carbon shells (denoted as C@MoS2 nanoboxes). The N-doped carbon shells can greatly improve the conductivity of the hybrid structure and effectively prevent the aggregation of MoS2 nanosheets. The ultrathin MoS2 nanosheets could provide more active sites for electrochemical reactions. When evaluated as an anode material for lithium-ion batteries, these C@MoS2 nanoboxes show high specific capacity of around 1000 mAh g(-1), excellent cycling stability up to 200 cycles, and superior rate performance. Moreover, they also show enhanced electrocatalytic activity for the electrochemical hydrogen evolution.

An FeCo alloy covered with nitrogen doped graphene is prepared by direct annealing of Fe₃[Co(CN)₆]₂nanoparticles, exhibiting efficient HER catalysis.

Currently, RuO2 is a benchmark acidic oxygen evolution reaction (OER) catalyst. Nevertheless, its wide applications are always restricted by slow dynamics and limited durability. This paper reports a type of Mn-doped RuO2 nanocrystals for boosting the OER catalytic performance in acidic media. The catalyst (named Mn-RuO2) is prepared through annealing of Ru-exchanged Mn-based derivative at 300 °C. Such Mn-RuO2 exhibits excellent acidic OER activity, with an overpotential of 158 mV at 10 mA cm–2 and a stability of 5000 cycles in the presence of sulfuric acid (0.5 mol/L). Both structural characterization and theoretical analysis show that the Mn doping in RuO2 can tune the d-band center of Ru active sites and lower antibonding surface-adsorbate states, which leads to a decreased free energy of the rate-determining step, ultimately enhancing the intrinsic activity of RuO2.

Red phosphorus (P) has attracted intense attention as promising anode material for high‐energy density sodium‐ion batteries (NIBs), owing to its high sodium storage theoretical capacity (2595 mAh g −1 ). Nevertheless, natural insulating property and large volume variation of red P during cycling result in extremely low electrochemical activity, leading to poor electrochemical performance. Herein, the authors demonstrate a rational strategy to improve sodium storage performance of red P by confining nanosized amorphous red P into zeolitic imidazolate framework‐8 (ZIF‐8) ‐derived nitrogen‐doped microporous carbon matrix (denoted as P@N‐MPC). When used as anode for NIBs, the P@N‐MPC composite displays a high reversible specific capacity of ≈600 mAh g −1 at 0.15 A g −1 and improved rate capacity (≈450 mAh g −1 at 1 A g −1 after 1000 cycles with an extremely low capacity fading rate of 0.02% per cycle). The superior sodium storage performance of the P@N‐MPC is mainly attributed to the novel structure. The N‐doped porous carbon with sub‐1 nm micropore facilitates the rapid diffusion of organic electrolyte ions and improves the conductivity of the encapsulated red P. Furthermore, the porous carbon matrix can buffer the volume change of red P during repeat sodiation/desodiation process, keeping the structure intact after long cycle life.

Nanoframe-like hollow structures with unique three-dimensional (3D) open architecture hold great promise for various applications. Current research efforts mainly focus on frame-like noble metals and metal oxides. However, metal sulfides with frame-like nanostructures have been rarely reported. Starting from metal-organic frameworks (MOFs), we demonstrate a novel structure-induced anisotropic chemical etching/anion exchange method to transform Ni-Co Prussian blue analogue (PBA) nanocubes into NiS nanoframes with tunable size. The reaction between Ni-Co PBA nanocube templates and Na2 S in solution leads to the formation of well-defined NiS nanoframes. The different reactivity between the edges and the plane surface of the Ni-Co PBA nanocubes is found to be the key factor for the formation of NiS nanoframes. Benefitting from their structural merits including 3D open structure, small size of primary nanoparticles, high specific surface area, and good structural robustness, the as-derived NiS nanoframes manifest excellent electrochemical performance for electrochemical capacitors and hydrogen evolution reaction in alkaline electrolyte.

Abstract Single-atom catalysts (SACs) exhibit intriguing catalytic performance owing to their maximized atom utilizations and unique electronic structures. However, the reported strategies for synthesizing SACs generally have special requirements for either the anchored metals or the supports. Herein, we report a universal approach of electrochemical deposition that is applicable to a wide range of metals and supports for the fabrication of SACs. The depositions were conducted on both cathode and anode, where the different redox reactions endowed the SACs with distinct electronic states. The SACs from cathodic deposition exhibited high activities towards hydrogen evolution reaction, while those from anodic deposition were highly active towards oxygen evolution reaction. When cathodically- and anodically-deposited Ir single atoms on Co 0.8 Fe 0.2 Se 2 @Ni foam were integrated into a two-electrode cell for overall water splitting, a voltage of 1.39 V was required at 10 mA cm −2 in alkaline electrolyte.

Self-supported nanotube arrays of sulfur-doped TiO2 on metal substrates are fabricated using electrochemical anodization and subsequent sulfidation. The nanotube arrays can serve as an efficient anode for sodium storage, enabling ultrastable cycling (retaining 91% of the 2nd capacity up to 4400 cycles) and robust rate capability (167 mA h g−1 at 3350 mA g−1), remarkably outperforming any other reported TiO2-based electrodes. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

A heterogeneous catalyst made of well-defined Co3O4 hexagonal platelets with varied exposed facets is coupled with [Ru(bpy)3]Cl2 photosensitizers to effectively and efficiently reduce CO2 under visible-light irradiation. Systematic investigation based on both experiment and theory discloses that the exposed {112} facets are crucial for activating CO2 molecules, giving rise to significant enhancement of photocatalytic CO2 reduction efficiency. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Abstract Exploring highly efficient and low‐cost electrocatalysts for electrochemical water splitting is of importance for the conversion of intermediate energy. Herein, the synthesis of dual‐cation (Fe, Co)‐incorporated NiSe 2 nanosheets (Fe, Co‐NiSe 2 ) and systematical investigation of their electrocatalytic performance for water splitting as a function of the composition are reported. The dual‐cation incorporation can distort the lattice and induce stronger electronic interaction, leading to increased active site exposure and optimized adsorption energy of reaction intermediates compared to single‐cation‐doped or pure NiSe 2 . As a result, the obtained Fe 0.09 Co 0.13 ‐NiSe 2 porous nanosheet electrode shows an optimized catalytic activity with a low overpotential of 251 mV for oxygen evolution reaction and 92 mV for hydrogen evolution reaction (both at 10 mA cm −2 in 1 m KOH). When used as bifunctional electrodes for overall water splitting, the current density of 10 mA cm −2 is achieved at a low cell voltage of 1.52 V. This work highlights the importance of dual‐cation doping in enhancing the electrocatalyst performance of transition metal dichalcogenides.