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Moisture-electric generators (MEGs), harvesting ubiquitous moisture from the environment for electricity generation, have attracted great interest as power supply devices. However, there are great challenges associated with material availability, fabrication accessibility and operation environment, which are key factors to achieve high output with low cost for practical applications, and a deeper understanding of the underlying mechanism of interactions between MEGs and water is urgently required. Here, a whey protein available in supermarkets is used to fabricate low-cost MEGs with controllable performance through tuning surface charges and hydrophilicity, which provides new insights into the electricity generation mechanism and large-scale application. The MEGs exhibit the highest voltage output of 1.45 V at a room humidity level of 40% relative humidity. The whey protein films possess the merits of low cost (70 times cheaper than commonly used polymers), being flexible and semi-transparent, and having self-healing ability, presenting excellent comprehensive device performance. Besides, MEGs can operate well at extreme temperatures (-20 degrees C or 50 degrees C) and power a location tracker in a desert with 26% relative humidity. The modified functional layers with selective ion absorption and controllable outputs provided a deeper understanding of electricity generation in MEGs and demonstrated great potential in powering a wide range of electronic devices in various dynamic environments with high sustainability and reliability. Refereed/Peer-reviewed

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Energy Letters, copyright © 2022 American Chemical Society, after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsenergylett.2c02040. Electronic doping is a promising approach to modulating the optoelectronic properties of semiconductors, but its effect on optoelectronic behaviors of halide perovskites remains controversial. Here, we comprehensively investigate the impact of Pb substitution in n-type CsPbIBr2 perovskite by utilizing monovalent Ag, divalent Zn, and trivalent Sb. Our findings reveal that the trap densities in doped CsPbIBr2 films are in the order of Ag < Zn < Sb. Compared with the pristine CsPbIBr2, the Ag-doped perovskite features a significantly reduced phase separation; however, the Sb doping accelerates halide segregation, and Zn exerts a negligible influence. The p-doping effect from monovalent Ag can shift the Fermi level of CsPbIBr2 toward the intrinsic midgap, which helps prevent the formation of ionic defects and reduce the migration of halide ions in the perovskite lattice. Through combing the density functional theory simulation, this study discloses the correlation between valence-controlled metal doping and phase segregation, providing a guideline for judiciously doping mixed-halide perovskites for optoelectronic applications.

This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials and Interfaces, copyright © 2022 American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acsami.2c02675. Metallic 1T-phase MoS2 exhibits superior hydrogen evolution reaction (HER) performance than natural 2H-phase MoS2 owing to its higher electrical conductivity and abundance of active sites. However, the reported 1T-MoS2 catalysts usually suffer from extreme instability, which results in quick phase transformation at ambient conditions. Herein, we present a facile approach to engineer the phase of MoS2 by introducing intercalated hydrazine. Interestingly, the as-synthesized 1T-dominant MoS2 sample demonstrates excellent ambient stability without noticeable degradation for 3 months. Additionally, the 1T-dominant MoS2 exhibits superior electrical conductivity (~700 times higher than that of 2H-MoS2) and improved electrochemical catalytic performance (current density ~12 times larger than that of 2H-MoS2 at an overpotential of 300 mV vs the reversible hydrogen electrode, RHE). Through experimental characterizations and density functional theory (DFT) calculation, we conclude that the stabilization of the metallic phase could be attributed to the electron donation from hydrazine molecules to the adjacent Mo atoms. The phase control strategy in this work provides a guideline to develop other highly efficient and stable two-dimensional (2D) electrocatalysts.

In view of the drawbacks of high-cost and inherent brittleness of indium tin oxide (ITO) based transparent electrodes, silver nanowires (AgNW) networks have been considered as promising alternative...

Artificial synapses are memristor-based devices mimicking biological synapses, and they are used in neuromorphic computing systems that process information in a parallel, energy efficient way and store information in an analog, non-volatile form. The next generation of computing systems are anticipated to use memristive circuits, as they can overcome the shortcomings of the von Neumann computer architecture in which the levels of memory and the CPU are separated, creating a bottleneck that causes energy-loss during information transfer. Memristors are utilized to build Resistive Random Access Memory (RRAM) that allows for multi-level data storage and construction of self-correcting, autonomous learning systems that can solve complex computational tasks that have historically required super-computing hardware. Artificial synapses have received attention since HP Labs fabricated the first practical memristor device. In this review we summarize the working principles, device architectures, fabrication and processing techniques, as well as the strategies for materials selection including binary metal oxide, perovskite, polymer, and organic materials. We also discuss the applications and challenges of using artificial synapses in artificial intelligence tasks such as image recognition, tactile sensing and speech recognition.

Refereed/Peer-reviewed As an emerging candidate for a sustainable power supply, moisture-electric generators (MEGs) have attracted great attention in recent years. Unlike the conventional hydroelectric system, MEGs propose to harvest energy from ambient moisture, driven by either ion diffusion under a concentration gradient or the interaction between a solid-liquid interface governed by electrostatic theory. Two-dimensional (2D) nanomaterials, in particular hydrophilic graphene oxide (GO), have been considered as the most promising materials for high-performance MEGs owing to their unique structure and properties. In line with the development of 2D nanomaterials, the recent electrical output of a single MEG has been greatly raised from tens to hundreds of millivolts, which is capable of powering commercial electronics. Herein, we have reviewed the recent progress of 2D nanomaterials in MEGs. The mechanism of moisture-induced electricity generation and strategies for tailoring 2D nanomaterials to enhance the output performance of MEGs are discussed. The potential application of MEGs is also discussed in two categories: sensing and power supply. Finally, the existing challenges and the perspective of MEGs are proposed for future study.

Harvesting energy from ubiquitous moisture is attracting growing interest for directly powering electronic devices. However, it is still challenging to fabricate high-performing moisture-electric generators (MEGs) with high and stable electric output. Herein, we report a simple strategy to modify the oxygen-based groups of graphene oxide using hydrochloric acid treatment, which boosts the electric output based on the device structure of graphene oxide/polyvinyl alcohol (GO/PVA) MEGs. The resulting MEG enables a stable voltage of 0.85 V and a current of 9.28 µA (92.8 µA·cm-2), which are among the highest values reported so far. More excitingly, electric output gets further improved by simply assembling four MEG units in series or parallel. Moreover, the MEG shows great commercial potential for flexible and wearable applications. Driven by these advancements, the assembled MEGs can successfully power sensors and calculators. This work opens a new era of advance for a new energy conversion technology able to directly powering electronic devices. C.C. acknowledges support from the Spanish Ministry of Science, Innovation and Universities under the "Ramon y Cajal" fellowship RYC2018-024947-I

Refereed/Peer-reviewed Power generation by converting energy from the ambient environment has been considered a promising strategy for developing decentralized electrification systems to complement the electricity supply for daily use. Wet gases, such as water evaporation or moisture in the atmosphere, can be utilized as a tremendous source of electricity by emerging power generation devices, that is, moisture-enabled-electric nanogenerators (MEENGs). As a promising technology, MEENGs provided a novel manner to generate electricity by harvesting energy from moisture, originating from the interactions between water molecules and hydrophilic functional groups. Though the remarkable progress of MEENGs has been achieved, a systematic review in this specific area is urgently needed to summarize previous works and provide sharp points to further develop low-cost and high-performing MEENGs through overcoming current limitations. Herein, the working mechanisms of MEENGs reported so far are comprehensively compared. Subsequently, a systematic summary of the materials selection and fabrication methods for currently reported MEENG construction is presented. Then, the improvement strategies and development directions of MEENG are provided. At last, the demonstrations of the applications assembled with MEENGs are extracted. This work aims to pave the way for the further MEENGs to break through the performance limitations and promote the popularization of future micron electronic self-powered equipment.

A great variety of complex networks can be well represented as random graphs with some constraints: for instance, a provided degree distribution, a smaller diameter, and a higher clustering coefficient. Among them, the degree distribution has attracted considerable attention from various science communities in the last few decades. In this paper, we focus mainly on a family of random graphs modeling complex networks that have an exponential degree distribution; i.e., P ( k ) ∼ exp ( α k ), where k is the degree of a vertex, P ( k ) is a probability for choosing randomly a vertex with degree equal to k, and α is a constant. To do so, we first introduce two types of operations: type-A operation and type-B operation. By both the helpful operations, we propose an available algorithm A for a seminal model to construct exactly solvable random graphs, which are able to be extended to a graph space S ( p , p c , t ) with probability parameters p and p c satisfying p + p c = 1. Based on the graph space S ( p , p c , t ), we discuss several topological structure properties of interest on each member N ( p , p c , t ) itself and find model N ( p , p c , t ) to exhibit the small-world property and assortative mixing. In addition, we also report a fact that in some cases, two arbitrarily chosen members might have completely different other topological properties, such as the total number of spanning trees, although they share a degree distribution in common. Extensive experimental simulations are in strong agreement with our analytical results.

Stainless steel plant dust is a hazardous by-product of the stainless steelmaking industry. It contains large amounts of Fe, Cr, and Ni, and can be potentially recycled as a raw material of inorganic black pigment in the ceramic industry to reduce environmental contamination and produce value-added products. In this paper, ceramic tiles prepared with black pigment through recycling of stainless steel plant dust were characterized in terms of physical properties, such as bulk density, water absorption, apparent porosity, and volume shrinkage ratio, as well as the long-term leaching behavior of heavy metals (Cr, Ni, Pb, Cd, and Zn). The results show that good physical properties of ceramic tiles can be obtained with 8% pigments addition, sample preparation pressure of 25 MPa, and sintering at 1200 ºC for 30 min. The major controlling leaching mechanism for Cr and Pb from the ceramic tiles is initial surface wash-off, while the leaching behavior of Cd, Ni, and Zn from the stabilized product is mainly controlled by matrix diffusion. The reutilization process is safe and effective to immobilize the heavy metals in the stainless steel plant dust.Stainless steel plant dust is considered as a hazardous material, and it can be potentially recycled for black pigment preparation in the ceramic industry. This paper provides the characteristics of the ceramic tiles with black pigment through recycling stainless steel plant dust, and the long-term leaching behavior and controlling leaching mechanisms of heavy metals from the ceramic tile. The effectiveness of the treatment process is also evaluated.