Here, we fabricated a pyridine-copolymerized g-C₃N₄ by a novel and cost-effective approach based on Schiff-base chemistry. Thus produced g-C₃N₄ showed significantly enhanced and stable visible-light photocatalytic H₂ evolution performance compared to pristine g-C₃N₄ obtained from urea. Subsequently, we constructed a composite of pyridine-modified g-C₃N₄ and N-doped reduced graphene oxide (N-rGO) by facile one-pot calcination to elevate the photocatalytic efficiency further. The peak H₂ production rate achieved using this composite was 304 μmol·h^-1, about 11.7 and 3.1 times as those obtained using pure g-C₃N₄ and pyridine-modified g-C₃N₄, respectively. In addition to enhanced visible light absorbance and enlarged surface area, the promoted separation, transfer, and surface reactivity of photogenerated charge carriers by the pyridine ring as intramolecular electron acceptor and N-rGO as "electron-transfer activation region" are considered responsible for the remarkably enhanced photocatalytic activity.

Owing to their unique optical, electronic, magnetic, and surface plasmon resonance properties, nanomaterials have attracted significant attention for potential bioanalysis and biomedical applications. Aptamers are single-stranded oligonucleotides, which are generated by a procedure termed as SELEX (Systematic Evolution of Ligands by EXponential Enrichment) and typically demonstrate high affinity and selectivity toward their target molecules. As a result of their unique characteristics, aptamers are promising recognition units that can be conjugated with nanomaterials for cancer cell imaging, diagnosis, and cancer therapy. By integrating the recognition abilities of aptamers with the properties of nanomaterials, aptamer-conjugated nanomaterials can serve as extraordinary tools for bioimaging and cancer therapy. Recently, aptamer-conjugated nanomaterials have attracted significant attention in the field of specific cancer cell targeted therapy owing to their improved efficacy and lower toxicity. In this review, we summarize the progress achieved of aptamer-conjugated nanomaterials as nanocarriers for specific cancer cell diagnosis and targeted therapy. In addition to drug delivery for cancer therapy, the various achievements of the aptamer-conjugated nanomaterials in combination with other emerging technologies to improve the efficiency and selectivity of cancer therapy have also been reviewed.

Lithium-sulfur (Li-S) batteries are promising electrochemical energy storage systems because of their high theoretical energy density, natural abundance, and environmental benignity. However, several problems such as the insulating nature of sulfur, high solubility of polysulfides, large volume variation of the sulfur cathode, and safety concerns regarding the lithium anode hinder the commercialization of Li-S batteries. Graphene-based materials, with advantages such as high conductivity and good flexibility, have shown effectiveness in realizing Li-S batteries with high energy density and high stability. These materials can be used as the cathode matrix, separator coating layer, and anode protection layer. In this review, the recent progress of graphene-based materials used in Li-S batteries, including graphene, functionalized graphene, heteroatom-doped graphene, and graphene-based composites, has been summarized. And perspectives regarding the development trend of graphene-based materials for Li-S batteries have been discussed.

The past decade has witnessed tremendous progress in the improvement of the electrocatalytic efficiency of the oxygen reduction reaction (ORR), which is important for the widespread adoption of fuel cells. This review provides an overview of the recent advances in the rational structural design and construction of Pt-based nanocatalysts to achieve higher ORR activity, with an emphasis on tuning the dimensionalities of Pt-based nanocrystals. The advantages and disadvantages of each dimensional catalyst have been discussed. In particular, we focus on a contemporary understanding of the structure-performance relationships based on the combined theoretical and experimental evidence, which can be further applied to guide the search for more exciting catalytic systems. The review concludes with a personal perspective for future research directions.

In this study, two novel difluorobenzothiadiazole (DFBT)-based polymeric donors, poly[(5, 6-difluoro-benzo[c][1, 2, 5]thiadiazol-4, 7-yl)-alt-((E)-2, 3-bis(3'-(2-octyldodecyl)-(2, 2'-bithiophen)-5, 5'-yl) acrylonitrile)] (DFBT812) and poly[(5, 6-difluoro-benzo[c][1, 2, 5]thiadiazol-4, 7-yl)-alt-((E)-2, 3-bis(3'-(2-decyltetradecyl)-(2, 2'-bithiophen)-5, 5'-yl) acrylonitrile)] (DFBT1014), possessing 2-octyldodecyl and 2-decyltetradecyl side chains, respectively, were designed, synthesized, and applied for polymer solar cells. Alkyl chains of 2-octyldodecyl and 2-decyltetradecyl were incorporated into the polymer to tune the solubility and crystallization of the polymers and morphology of the blend films. Morphological study showed that the blend film of DFBT812 with PC₆₁BM presented much better phase separation domain, which is beneficial for charge transport and collection of charge carriers in the blend film. Photovoltaic devices based on DFBT812 exhibited a power conversion efficiency (PCE) of 6.25%, outperforming those based on DFBT1014. Moreover, DFBT812-based photovoltaic devices exhibited a PCE over 6% even when the thickness of the active layer was 220 nm.

In addition to being the energy powerhouse of the cell, mitochondria are an important source of reactive oxygen species (ROS) during the process of molecular oxygen metabolism. Mitochondrial ROS are closely associated with normal physiological functions as well as human diseases, and participate in cell signaling, nucleic acid and protein damage, and oxidative stress induction. However, the complicated interplay between mitochondrial ROS and the cellular pathological state has not been fully elucidated. It is expected that research on the mitochondrial ROS undertaking in the molecular pathogenesis of human diseases would benefit from development of efficient tools for the detection of these ROS. In recent years, an increasing number of fluorescent probes for mitochondrial ROS with high sensitivity and selectivity have been developed. Here, we present a review of the recent advances in small molecular fluorescent probes for selective detection of ROS inside the mitochondria. In this review, the design, synthesis, characteristics, and applications of the published fluorescent probes for mitochondrial ROS are discussed in detail.

Solution-processable organic photovoltaic cells (OPVs) have attracted considerable interest.Over the past twenty years, fullerene and its derivatives have been predominately used as the electron acceptor materials to fabricate OPV devices.In recent few years, non-fullerene organic photovoltaic cells (NF-OPVs), consisting of polymers as the donors and the non-fullerene (NF) materials as the acceptors, have been developed rapidly, and the highest power conversion efficiencies of NF-OPVs exceed those of fullerene-based OPVs.In these NF-OPVs, both polymeric donor materials and NF acceptors play critical roles in achieving outstanding efficiencies, and hence, the molecular design of the polymer donors has been deemed a very important topic of research in the field.In this review, we will present an introduction of the specific requirements for polymer donors in NF-OPVs and summarize the recent progress related to polymer donors for the applications in highly efficient NF-OPVs.

In response to aggravated fossil resources consuming and greenhouse effect, CO₂ reduction has become a globally important scientific issue because this method can be used to produce value-added feedstock for application in alternative energy supply. Photoelectrocatalysis, achieved by combining optical energy and external electrical bias, is a feasible and promising system for CO₂ reduction. In particular, applying graphene in tuning photoelectrochemical CO₂ reduction has aroused considerable attention because graphene is advantageous for enhancing CO₂ adsorption, facilitating electrons transfer, and thus optimizing the performance of graphene-based composite electrodes. In this review, we elaborate the fundamental principle, basic preparation methods, and recent progress in developing a variety of graphene-based composite electrodes for photoelectrochemical reduction of CO₂ into solar fuels and chemicals. We also present a perspective on the opportunities and challenges for future research in this booming area and highlight the potential evolution strategies for advancing the research on photoelectrochemical CO₂ reduction.

Functional materials and devices that can efficiently store and convert energies have attracted a great deal of attention in recent years. The composites of layered double hydroxide and graphene (LDH/G) are important energy materials. They have excellent physical and chemical properties of both components. Furthermore, their performances in energy-related systems can be improved by increasing the electrical conductivity of LDHs by blending graphene and partly preventing the aggregation of graphene sheets using LDH nanostructures. Therefore, LDH/G composites can be used in various energy applications, particularly for developing high-performance supercapacitors and efficient electrocatalysts for electrochemical splitting of water. In this review, we summarize the recent advances on the synthesis of LDH/chemically modified graphene (CMG, e.g., graphene oxide, reduced graphene oxide and their derivatives) composites and their application in electrochemical energy storage and conversion. Furthermore, the challenges and future perspectives in this research field are also outlined.

Multifunctional theranostic agents that are responsive to external physical stimuli such as light, magnetic field, ultrasound, radiofrequency, and X-rays have been widely explored for their use in physical stimulus-responsive therapies for cancer.Encouraging results in many preclinical animal experiments have been obtained; thus, this innovative strategy has gained great attention.Owing to the nontoxicity of physical stimulus-responsive agents and treatment specificity under particular external stimuli, physical stimulus-responsive cancer therapies provide greatly reduced toxicity and enhanced therapeutic efficiency compared with conventional chemotherapeutic agents.When combining physical stimulus-responsive therapies with other traditional therapeutics, synergistic antitumor effects via various mechanisms can be achieved.In this review, we will summarize the recent developments in physical stimulus-responsive therapies and discuss the important roles of nanoscale theranostic agents in these novel treatment modalities.

Radiation therapy kills tumor cells via focused high energy radiation, and has become one of the most common and effective clinical treatments for malignant tumors. However, some limitations restrict its clinical efficacy, including a requirement for elevated doses of radiation, side effects due to exposure of healthy tissue, and especially radioresistance of tumor cells. With the development of nanomedicine, multifunctional nanoradiosensitizers offer a new route to improve the efficiency of radiation therapy. In this paper, we summarize the main types of nanoradiosensitizers and their applications in radiation therapy, especially those that have currently entered clinical trials. We also summarize the main approaches to nanomaterials-based radiosensitization, and discuss the factors influencing their application. Finally, the challenges and prospects of multifunctional nanoradiosensitizers are presented.

A solid polymer electrolyte (SPE), composed of sodium bis(trifluoromethanesulfonyl)imide (NaTFSI) and poly(ethylene oxide) (PEO), is prepared by a simple solution-casting method. The physicochemical and electrochemical properties of the NaTFSI/PEO ([EO]/[Na⁺]=15) SPE in terms of its phase transitions, crystallization, thermal stability, ionic conductivity, and anodic electrochemical stability are systematically investigated. We demonstrate that the NaTFSI/PEO SPE has a relatively high ionic conductivity (σ ≈ 10^-3 S·cm^-1) at 80℃, excellent electrochemical stability (4.86 V vs. Na⁺/Na), and thermal stability up to 350℃. More importantly, the NaTFSI-based SPE delivers not only excellent chemical and electrochemical stability with sodium metal, but also good cycling and rate performances in an Na|SPE|NaCu_1/9Ni_2/9Fe_1/3Mn_1/3O₂ cell.

White LEDs are considered the next-generation light source as they are environmentally friendly and have high efficiencies. Therefore, researches are being conducted to meet the performance requirements of phosphors, which are the crucial components of white LEDs. Eu²⁺ and Eu³⁺ ions have different electronic structures, which lead to distinct photoluminescence properties. The characteristic emissions of Eu²⁺ and Eu³⁺ originate from the 4f-4f and 4f-5d transitions, respectively. In order to combine their respective features, the research of mixed-valence Eu ions into single-phase phosphors has become a hot research topic in recent years. The mixed-valence Eu ion-doped phosphors have tunable luminescence properties because they possess the respective properties of Eu²⁺ and Eu³⁺. From their respective characters of Eu²⁺ and Eu³⁺, this paper mainly reviews the progress of mixed valence Eu(+2, +3) ion-activated single-component luminescent materials in recent years from three aspects: unbalanced substitution, crystal field regulation, and other systems. In addition, the respective photoluminescence properties of Eu²⁺ and Eu³⁺ and the luminescence performances and mechanisms of the mixed-valence Eu ion-activated phosphors have been summarized. The luminescence performances and mechanisms have been summarized as well. All the research works carried out in this field provide inspiration for the investigation of new phosphors.

Au/TiO₂/MoS₂ plasmonic composite photocatalysts were synthesized via deposition-precipitation with urea. The photocatalytic activities of the prepared samples were evaluated by performing hydrogen production experiments under Xe lamp irradiation with a 10% (φ, volume fraction) glycerol aqueous solution as the sacrificial agent. The results showed that the optimal content of MoS₂ in the Au/TiO₂/MoS₂ composite is 0.1% (w, mass fraction) and the corresponding H₂ production rate was 708.85 μmol·h^-1, which was almost 11 times higher than that of TM6.0 with the strongest photocatalytic activity in the all binary TiO₂/MoS₂ composites. The enhanced photocatalytic activity of the ternary Au/TiO₂/MoS₂ composites is mainly due to the surface plasmon resonance of the supported Au nanoparticles absorbed on the TiO₂/MoS₂ layered composite, which show an intense absorption maximum centered around 550–560 nm and induce the photoexcitation of electrons. Meanwhile, the electrons excited by surface plasmon resonance of Au could be injected into the conduction band of TiO₂, and they were then transferred to the edges of MoS₂ for catalyzing the production of H₂.

Two new coordination polymers, namely, [[Zn₂(TTR4A)(L)₂]·DMF·4H₂O]_n (compound 1) and [[Co(TTR4A)Cl₂]·DMA·H₂O]_n (compound 2), have been synthesized under solvothermal conditions (TTR4A = tetrakis(1, 2, 4-triazol-ylmethylresorcin[4]arene), L = 4, 4'-biphenyldicarboxylic acid, DMF = N, N-dimethylformamide and DMA = N, N-dimethylacetamide). Crystal structures of the coordination compounds 1 and 2 were determined by single-crystal X-ray diffraction analyses, and further characterized by infrared spectra, elemental analyses, powder X-ray diffraction, and thermogravimetric analyses. In coordination compound 1, four L ligands bridge four adjacent Zn(Ⅱ) atoms to generate macrocyclic Zn₄L₄ units, which are further linked by the TTR4A ligands into a one-dimensional chain structure. In coordination compound 2, four 1, 2, 4-triazole groups of each TTR4A ligand bridge four Co(Ⅱ) atoms to form a two-dimensional layer structure. Furthermore, studies on the luminescent properties of compound 1 in solid state at room temperature reveal that it exhibits an intense emission peak. Luminescent-sensing detections for Fe³⁺, Cr₂O₇²⁻, and nitrobenzene solvents were also investigated by using compound 1 as the potential luminescent sensor.