Abstract Three‐dimensional (3D) printing has the potential to revolutionize the way energy storage devices are designed and manufactured. In this paper, we explore the use of 3D printing in the design and production of energy storage devices, especially zinc‐ion batteries (ZIBs) and examine its potential advantages over traditional manufacturing methods. 3D printing could significantly improve the customization of ZIBs, making it a promising strategy for the future of energy storage. In particular, 3D printing allows for the creation of complex, customized geometries, and designs that can optimize the energy density, power density, and overall performance of batteries. Simultaneously, we discuss and compare the impact of 3D printing design strategies based on different configurations of film, interdigitation, and framework on energy storage devices with a focus on ZIBs. Additionally, 3D printing enables the rapid prototyping and production of batteries, reducing leading times and costs compared with traditional manufacturing methods. However, there are also challenges and limitations to consider, such as the need for further development of suitable 3D printing materials and processes for energy storage applications.

Abstract The crystal phases are essential to the physicochemical properties and functionalities of materials. Copper selenide has emerged as an important and appealing semiconductor, which can exist in a variety of polymorphic phases. However, the richness of polymorphs also makes it a challenge to the direct preparation of copper selenide nanocrystals with tunable phases. Herein, two polymorphs, that is, quasi‐tetragonal Cu2−xSe nanocubes and metastable wurtzite Cu2Se nanodisks, are successfully synthesized by using a single precursor, copper(I) selenocyanate (CuSeCN), as the Cu and Se sources. The key to phase modulation is the optimal choice of the ligand in the synthesis. The as‐prepared nanocrystals possess different morphologies and compositions, giving rise to distinct optical properties and electrical conductivities. Interestingly, the copper selenide nanocrystals can provide a platform for the rational construction of two types of amorphous hollow Au─Cu─Se nanostructures by reaction with Au(I) precursor, in which their final shapes are well kept as that of the original nanocrystal templates. This work provides an easy strategy for the phase‐controlled synthesis of copper selenide nanocrystals and enables the design of new materials for broad applications.

Abstract Electronic fibers/textiles have great potential for applications in smart wearables due to their excellent flexibility, air permeability, and wearing comfort. However, it is still challenging to produce reliable electronic textiles at low cost and in a large scale. Herein, we report a spraying‐spinning process for fabricating electronic yarns with excellent stability and durability. Cotton sliver, which is the raw material for spinning conventional cotton yarns, was spray coated with carbon nanotubes (CNTs) and spun on an Ag@nylon yarn, forming a sheath‐core structured CNT@cotton‐Ag@nylon yarn (CCAY). The process is continuous, large‐scalable, applicable to other raw fiber materials and compatible with traditional textile processes. The as‐prepared CCAY showed superior mechanical durability, washability, and conductivity to typical surface coated yarns. It can be easily processed or integrated into textiles through weaving, knitting, sewing, and embroidering. We systematically studied the electromechanical, electro‐thermal, and photothermal performance of CCAY based yarns/fabrics, demonstrating its versatile applications in smart textiles. In addition, CCAY can be further equipped with other features, such as electro‐thermochromic functions, pH sensing and flame resistant abilities. Considering the large‐scalability, versatility, and low‐cost, we foresee that this spraying‐spinning process for electronic yarns may play important roles in the development of practical smart fibers/textiles.

Outside front cover image: In the field of catalysis, the intentional introduction of defects is an advanced material design strategy. In this work, plasma functionalized defective MoSe2 is prepared for electrochemical sensing of H2O2. The tailored Se vacancies and N dopants generate new active sites, expose more edge active surfaces, narrow the bandgap, and strengthen binding with •OH. The sensor delivers competitive sensing performance in an ultra-wide pH range and a portable SPE sensor is developed to demonstrate the significant commercial potential. This work provides insights into plasma surface modification of 2D catalytic materials. (DOI: 10.1002/smm2.1089)

Front cover image: Ruthenium-based electrocatalysts have great potential as an alternative to platinum-based materials for the electrolysis of water for hydrogen evolution. In this work, a unique two-site mechanism of the ruthenium single/dual atoms and Ru nanoclusters to strengthen the stability of single atom sites and enhance its intrinsic activity was identified. Ru S/DAs and Ru NCs demonstrate high electroactivity due to the electroactive Ru 4d orbitals. The introduction of Ru NCs activates the carbon support, providing a high electronic conductivity to transfer electrons from Ru NCs to Ru S/DAs, and facilitates water dissociation for the HER process. (DOI: 10.1002/smm2.1067)

Abstract High‐performance nondoped organic light‐emitting diodes (OLEDs) are promising technologies for future commercial applications. Herein, we synthesized two new thermally activated delayed fluorescence (TADF) emitters that enable us, for the first time, to combine three effective approaches for enhancing the efficiency of nondoped OLEDs. First, the two emitters are designed to have high steric hindrances such that their emitting cores will be suitably isolated from those of their neighbors to minimize concentration quenching. On the other hand, each of the two emitters has two stable conformations in solid films. In their neat films, molecules with the minority conformation behave effectively as dopants in the matrix composing of the majority conformation. One hundred percent exciton harvesting is thus theoretically feasible in this unique architecture of “self‐doped” neat films. Furthermore, both emitters have relatively high aspect ratios in terms of their molecular shapes. This leads to films with preferred molecular orientations enabling high populations of horizontal dipoles beneficial for optical out‐coupling. With these three factors, OLEDs with nondoped emitting layers of the respective emitters both achieve nearly 100% exciton utilization and deliver over 30% external quantum efficiencies and ultralow efficiency roll‐off at high brightness, which have not been observed in reported nondoped OLEDs.

Abstract Fluorescent carbon dots (CDs) have been widely studied in biosensing, imaging, information encryption, and optoelectronic devices due to excellent optical properties, such as photostability, tunable luminescence range, and resistance to photobleaching. In recent years, CDs have been explored for use in agriculture. Based on their light harvest and light conversion capacity, as well as their characteristics of easy synthesis and low toxicity, CDs show great potential in improving crop photosynthesis. In addition, CDs can also be used for smart and anticounterfeiting packing, food safety detection, and preservation of crops after harvest. In this study, the application of CDs with excellent optical properties in crops has been summarized, including preharvest processes (photosynthesis and plant imaging), and postharvest processes (crop preservation and food safety). Then the toxicity of CDs to crops is introduced. Finally, the present challenges and future prospects are discussed.

Abstract The quest for advanced energy storage devices with cheaper, safer, more resource‐abundant storage has triggered intense research into zinc ion batteries (ZIBs). Among them, organic materials as cathode materials for ZIBs have attracted great interest due to their flexible structure designability, high theoretical capacity, environmental friendliness, and sustainability. Although numerous organic electrode materials have been studied and different redox mechanisms have been proposed in the past decade, their electrochemical performance still needs further improvement, and the mechanisms require further exploration. This paper provides a systematical overview of three types of organic materials (bipolar‐type conductive polymer, n‐type conjugated carbonyl compounds, and p‐type material) on the energy storage mechanisms and distinct characteristics. We then focus on discussing the design strategies to improve electrochemical performance. Furthermore, the challenges and future research directions are discussed to provide a foundation for further developing organic‐based ZIBs.

Abstract Selective reduction of CO2 into liquid products such as ethanol through electrochemical catalysis is promising in storing renewable energy in more deliverable chemicals and balancing the carbon footprint in the environment. However, the lack of efficient catalysts for electrochemical CO2 reduction reaction (eCO2RR) makes the promise challenging because the formation of C2+ alcohols requires coupling reactions between the shallow reduction intermediates and deep reduction intermediates that are usually difficult to form on uniform catalyst surfaces simultaneously with appropriate transient kinetics. Herein, we report a new strategy for synthesizing bimetallic nanostructures with high densities of interfaced Ag/Cu boundaries, which facilitate the coupling reaction of the high‐oxidation‐number intermediates (CO) formed on the Ag surface and the low‐oxidation‐number intermediates (CHx) formed on the Cu surface. The synthesis relies on the electrochemical reduction of bilayered nanoplates made of silver thiolate and copper thiolate, resulting in Ag/Cu nanostructures exposing Ag surface, Cu surface, and the Ag/Cu interfaced boundaries. Balancing the accessible surface areas of the Ag surface, Cu surface, and Ag/Cu boundaries is beneficial for maximizing the activity and selectivity of eCO2RR towards ethanol production. Faradaic efficiency of forming ethanol has been observed as high as about 50% using the Ag/Cu nanostructure catalyst with molar ratio nAg:nCu of 1:1. Moreover, the promoted coupling reaction at the Ag/Cu boundaries and surface modification with thiolate anions significantly suppress the undesirable hydrogen evolution reaction, particularly at high cathodic potentials, maintaining high energy efficiency for eCO2RR.