Owing to the maximized utility of metal atoms and particular coordinate unsaturated sites, single-atom catalysts (denoted as SACs) become one of the most pioneering research fields in heterogeneous catalysis. Recent years have witnessed the rapid development of SACs in synthesis, characterization, and their superior catalytic performances in various reactions. This Perspective summarizes most recently progresses of SACs for thermal heterogeneous catalysis in liquid-phase, with a focus on the challenging selective hydrogenation and oxygenation reactions for synthesis of fine chemicals. Different kinds of SACs and the coordination environment of SACs are discussed for these reactions. Finally, current limitations and potential research areas are proposed.

The energy consumption of building for heating and cooling accounts for about 15% of the total energy consumption of the world. Owing to the rapid progress in nanophotonic materials, innovative technologies based on multispectral design and tuning have obtained significant development and provided new opportunities to decrease the energy consumption of buildings. Based on this background, this review aims to summarize state-of-the-art progress of daytime radiative cooling, smart windows, and personal thermal management toward net-zero energy buildings based on multispectral material and photonic engineering. Unsolved scientific and technical challenges associated with future perspectives in this field are also discussed, hoping to promote the development of building energy-saving technologies for our sustainable future.

Artificial intelligence memory is expected to acquire, calculate, and analyze a large amount of logical information and data in time to dynamically respond to artificial neural networks. It is the most promising candidate for realizing a new hardware artificial intelligence architecture that mimics biological neural networks. However, the research on artificial intelligence memory is still in the initial stage, and there are some unresolved bottlenecks for the preparation of artificial intelligence memory devices. Such as it require external power supplements for the operating of memory devices, resulting in high power consumption and difficulty in real-time neuromorphic computing. Fortunately, self-powered memory devices can perfectly solve the above problems. In this Review, we have systemically summarized the current development on material, integration, and technology for the self-powered memory application, as well as provide the prospect, suggestion, and optimization method for neuromorphic computing and artificial intelligence with self-powered memory.

Photoelectrochemical (PEC) hydrogen production can directly and effectively convert solar energy to clean and sustainable hydrogen energy. However, taking the photoanode as an example, the onset potential (Vonset) of the photoanodic current is too positive, which is not conducive to the improvement of energy conversion efficiency and thus hinders the practical application of PEC hydrogen production. Here, we demonstrate a new quaternary alloy nanowire photoanode with low Vonset and high solar conversion efficiency constructed by a narrow-bandgap semiconductor CdSeTe and a wide-bandgap semiconductor CdS, a strategy that enables the energy band modulation by adjusting the molar ratio of the two semiconductors. Through the modulation of the band structure, the negative shift in the Vonset of the PEC hydrogen production can be realized, so that high photocurrent is achieved under a lower bias voltage. As a result, we cathodically shifted the Vonset by 0.7 VRHE on the alloyed cadmium-based chalcogenide photoanode under 1-sun light. This strategy of using energy band modulation to achieve a lower Vonset and high energy conversion efficiency will provide more possibilities for the industrial application of PEC hydrogen production.

The development of economical and versatile catalysts is of both technological and fundamental interest in the synthesis of COFs. Imine COFs are a widely investigated class of COFs commonly synthesized via the Schiff base reaction that requires the use of acetic acid, elevated temperatures, reduced pressure, and long reaction periods. Here, we present group 14–15 metal halides as general and low-cost catalysts for the synthesis of imine COFs. The catalytic activity of lead, antimony, and bismuth halides is proved by the successful synthesis of a series of imine COFs with varying pore sizes and structural stability. Synthesis of highly crystalline COFs with surface areas up to 2522 m2/g is achieved. Mechanistic studies reveal that the dynamic imine exchange triggered by metal halides promotes the crystallization of COFs. The COF matrices formed under metal halide catalysis were used for in situ perovskite synthesis. The perovskite@COF composites maintain the integrity of COFs while enhancing the stability of perovskites by being embedded in COFs. This work expands the catalyst choice for imine-based COFs and provides a design paradigm for the synthesis of perovskite@COF composites for future applications.

Organic lasing dyes possessing small energy gaps commonly suffer from high thresholds, because of energy-gap law, which induces detrimental nonradiative relaxation. Herein, molecules based on alternating donor (D) and acceptor (A) moieties are described. Those linear molecules are built with a spacer between D and A, with a general formula of D–spacer–A–spacer–D. Such modification of the A core allows one to obtain color-tunable lasing properties from yellow to near-infrared (NIR). Into more details, triphenylamine (TPA) is selected as the D moiety, while benzothiadiazole (BTD) and benzo[1,2-c:4,5c′]bis[1,2,5]thiadiazole (BBTD) with strong electron-withdrawing capability, are chosen as A cores for yellow ((TPA-F)2BTD) and NIR ((TPA-F)2BBTD) lasing dyes, respectively. Both dyes exhibit high photoluminescence quantum yields (PLQYs) and fast fluorescence radiative rate. The corresponding amplified spontaneous emission (ASE) thresholds of yellow and NIR dyes are as low as 0.5 and 3.8 μJ cm–2 in the solution-processing blending films, with wavelength peaks at 550 and 811 nm, respectively. In those dyes, the long alkyl chains appended on the fluorene conjugated spacer guarantee the high solubility and prevent aggregation. Consequently, for (TPA-F)2BTD, the neat film allows one to reach PLQYs as high as 90%, with a low ASE threshold (1.9 μJ cm–2) and good stability. Therefore, such promising molecular design allows the realization of color-tunable ASE or lasing dyes with very low thresholds.

Lightweight aerogels with elastic performance and tunable surface properties have made them a good alternative for smart electornic skin. However, the aerogels remain a great barrier for sensing applications because of their severe brittleness and difficult regulation of surface property. Herein, we report a superelastic aerogel originated from a rational designed waterborne poly(siloxane-benzoxazine) by using the ice template method. The three-dimensional (3D) network is constructed via the radical crosslinking and ring-opening polymerization followed by the freeze-drying process. Moreover, it also shows pronounced mechanical performance that can be compressed over 70% and recover without fracture. Beyond that, its surface property could be altered from highly hydrophilic to hydrophobic property (145° water contact angle) by adjusting the crosslinking degree of the aerogel under different curing temperatures. We further demonstrate a pressure sensor by in situ polymerization of the aniline (PANI) on the surface of the aerogel. The multifunctional properties make it an attractive material for self-cleaning electronic skin.

Colloidal quantum dot (CQD) solar cells composed of ionic halide passivated active layers benefit from improved passivation and high carrier mobility because of short interparticle distance. However, non-ideal band alignment of the active layer limits the potential open-circuit voltage (VOC) produced by the solar cell. We initiated a suite of simulation-based studies of CQD solar cells and found a route to improved performance by increasing the degree of p-type behavior. Fluoride, while it is a p-type ionic ligand as desired, is incompatible with traditional ligand exchange processes. In prior studies, it has shown to etch the lead sulfide surface uncontrollably. Instead, we develop a multistep halide exchange method, in which the CQD active layer is doped with fluoride ions after ligand exchange. This new method prevents CQD surface etching without impeding charge transport, resulting in a statistically significant improvement in VOC, fill factor, and power conversion efficiency.

A class of solution-processable, donor–acceptor-decorated dithienophosphole oxide derivatives has been successfully synthesized and employed to fabricate solution-processed resistive memory devices with a simple indium–tin oxide/active layer/aluminum structure. The intramolecular charge transfer (ICT) characters of the donor–acceptor dithienophosphole oxide derivatives were established from photophysical, solvatochromic, and computational studies. The number of conductance states in the organic memory devices was found to be altered by slight changes in molecular structures. The mechanism for the tristable memory property of the devices was proposed based on the correlation of the extent of ICT characters and the computed structural parameters of the compounds, current–voltage characteristics of the devices and the fitting to theoretical conduction models. These findings offer important insights for the realization of multilevel resistive memory devices through the modification of the ICT character of the active compounds.