Electrolyte additives have been widely used to address critical issues in current metal (ion) battery technologies. While their functions as solid electrolyte interface forming agents are reasonably well‐understood, their interactions in the liquid electrolyte environment remain rather elusive. This lack of knowledge represents a significant bottleneck that hinders the development of improved electrolyte systems. Here, the key role of additives in promoting cation (e.g., Li+) desolvation is unraveled. In particular, nitrate anions (NO3−) are found to incorporate into the solvation shells, change the local environment of cations (e.g., Li+) as well as their coordination in the electrolytes. The combination of these effects leads to effective Li+ desolvation and enhanced battery performance. Remarkably, the inexpensive NaNO3 can successfully substitute the widely used LiNO3 offering superior long‐term stability of Li+ (de‐)intercalation at the graphite anode and suppressed polysulfide shuttle effect at the sulfur cathode, while enhancing the performance of lithium–sulfur full batteries (initial capacity of 1153 mAh g−1 at 0.25C) with Coulombic efficiency of ≈100% over 300 cycles. This work provides important new insights into the unexplored effects of additives and paves the way to developing improved electrolytes for electrochemical energy storage applications.

The photoelectrochemical (PEC) approach is attractive as a promising route for the nitrogen reduction reaction (NRR) toward ammonia (NH3) synthesis. However, the challenges in synergistic management of optical, electrical, and catalytic properties have limited the efficiency of PEC NRR devices. Herein, to enhance light‐harvesting, carrier separation/transport, and the catalytic reactions, a concept of decoupling light‐harvesting and electrocatalysis by employing a cascade n+np+‐Si photocathode is implemented. Such a decoupling design not only abolishes the parasitic light blocking but also concurrently improves the optical and electrical properties of the n+np+‐Si photocathode without compromising the efficiency. Experimental and density functional theory studies reveal that the porous architecture and N‐vacancies promote N2 adsorption of the Au/porous carbon nitride (PCN) catalyst. Impressively, an n+np+‐Si photocathode integrating the Au/PCN catalyst exhibits an outstanding PEC NRR performance with maximum Faradaic efficiency (FE) of 61.8% and NH3 production yield of 13.8 µg h–1 cm–2 at −0.10 V versus reversible hydrogen electrode (RHE), which is the highest FE at low applied potential ever reported for the PEC NRR.

Design and development of an efficient, nonprecious catalyst with structural features and functionality necessary for driving the hydrogen evolution reaction (HER) in an alkaline medium remain a formidable challenge. At the root of the functional limitation is the inability to tune the active catalytic sites while overcoming the poor reaction kinetics observed under basic conditions. Herein, we report a facile approach to enable the selective design of an electrochemically efficient cobalt phosphide oxide composite catalyst on carbon cloth (CoP-Co x O y /CC), with good activity and durability toward HER in alkaline medium (η 10 = −43 mV). Theoretical studies revealed that the redistribution of electrons at laterally dispersed Co phosphide/oxide interfaces gives rise to a synergistic effect in the heterostructured composite, by which various Co oxide phases initiate the dissociation of the alkaline water molecule. Meanwhile, the highly active CoP further facilitates the adsorption–desorption process of water electrolysis, leading to extremely high HER activity.

Water oxidation is a primary step in natural as well as artificial photosynthesis to convert renewable solar energy into chemical energy/fuels. Electrocatalytic water oxidation to evolve O2, utilizing suitable low-cost catalysts and renewable electricity, is of fundamental importance considering contemporary energy and environmental issues, yet it is kinetically challenging owing to the complex multiproton/electron transfer processes. Herein, we report the first cobalt-based pincer catalyst for catalytic water oxidation at neutral pH with high efficiency under electrochemical conditions. Most importantly, ligand (pseudo)­aromaticity is identified to play an important role during electrocatalysis. A significant potential jump (∼300 mV) was achieved toward a lower positive value when the aromatized cobalt complex was transformed into a (pseudo)­dearomatized cobalt species. The dearomatized species catalyzes the water oxidation reaction to evolve oxygen at a much lower overpotential (∼340 mV) on the basis of the onset potential (at a current density of 0.5 mA/cm2) of catalysis at pH 10.5, outperforming other Co-based molecular catalysts reported to date. These observations may provide a new strategy for the judicious design of earth-abundant transition-metal-based water oxidation catalysts.

The facile synthesis of hierarchically functional, catalytically active, and electrochemically stable nanostructures holds a tremendous promise for catalyzing the efficient and durable oxygen evolution reaction (OER) and yet remains a formidable challenge. Herein, we report the scalable production of core–shell nanostructures composed of carbon-coated cobalt diphosphide nanosheets, C@CoP2, via three simple steps: (i) electrochemical deposition of Co species, (ii) gas-phase phosphidation, and (iii) carbonization of CoP2 for catalytic durability enhancement. Electrochemical characterizations showed that C@CoP2 delivers an overpotential of 234 mV, retains its initial activity for over 80 h of continuous operation, and exhibits a fast OER rate of 63.8 mV dec–1 in base.

Seeking more economical alternative electrocatalysts without sacrificing much in performance to replace precious metal Pt is one of the major research topics in hydrogen evolution reactions (HER). Tungsten disulfide (WS 2 ) has been recognized as a promising substitute for Pt owing to its high efficiency and low-cost. Since most existing works adopt solution-synthesized WS 2 crystallites for HER, direct growth of WS 2 layered materials on conducting substrates should offer new opportunities. The future economy requires the production of clean energy to replace fossil fuels. Hydrogen is considered as one of the promising future options as a pollution-free energy carrier. Practically, electrocatalytic water splitting has gained attention for sustainable hydrogen production.1 Accordingly, scientists are eagerly seeking for an electrocatalyst that could act as an alternative to the most electrochemically active but expensive platinum metal.2-4 Tungsten disulfide, WS 2 , a member of the semiconducting transition metal dichalcogenide family, has drawn considerable attention due to its semiconducting nature and electrocatalytic activities. [5][6][7][8] Nevertheless, very few studies have been conducted on WS 2 regarding to HER up to date. 5,9-11 The systematic studies of layered WS 2 materials for HER are still not available. 1 Herein, we report our preparation of layered WS 2 electrocatalysts for highly efficient hydrogen production reaction.We have performed the growth of WS 2 by the thermolysis of ammonium tetrathiotungstate (NH 4 ) 2 WS 4 on conducting carbon cloth (CC) substrates under different gaseous environments. As CC is conducting with a high surface area, it is an ideal substrate for loading the WS 2 materials.1 The influence of environmental gas on the electrochemical activity of the obtained WS 2 catalysts were studied. H 2 S was found to give the WS 2 electrocatalysts with superior performance for the hydrogen production with a current density of 10 mA cm −2 at a low overpotential of 184 mV. Materials and MethodsMaterials.-All chemicals including sulfuric acid (H 2 SO 4 ) and ammonium tetrathiotungstate (NH 4 ) 2 WS 4 were purchased from commercial sources and used without further purification. Water used was purified through a Millipore system. Preparation of WS 2 .-The precursor, ammonium tetrathiotungstate solution ((NH 4 ) 2 WS 4 (Alfa Aesa 99.9%) in 5.0 wt% in DMF (dimethylformamide)), was casted on CC substrates (W0S1002 * Electrochemical Society Member.z E-mail: hkw@kaust.edu.sa from CeTech) with a loading amount of 1 mg/cm 2 (Scheme 1). The drop-casted conducting carbon cloth substrate was then baked on a hot plate at 160• C for 20 min. Subsequently, it was fed into the tube furnace for thermolysis process under atmospheric pressure (AP) at varied temperatures and in different gaseous environments, including H 2 S and Ar (10 and 90 sccm respectively), H 2 and Ar (10 and 90 sccm respectively), and pure Ar (100 sccm). In order to exclude oxygen species from the system, tube furnace was pumped and p...

M. (2019). Auto-combustion synthesis and characterization of perovskite-type LaFeO3 nanocrystals prepared via different routes. Ceramics International, 45(13),

Growing continuous monolayer films of transition-metal dichalcogenides (TMDs) without the disruption of grain boundaries is essential to realize the full potential of these materials for future electronics and optoelectronics, but it remains a formidable challenge. It is generally believed that controlling the TMDs orientations on epitaxial substrates stems from matching the atomic registry, symmetry, and penetrable van der Waals forces. Interfacial reconstruction within the exceedingly narrow substrate-epilayer gap has been anticipated. However, its role in the growth mechanism has not been intensively investigated. Here, we report the experimental conformation of an interfacial reconstructed (IR) layer within the substrate-epilayer gap. Such an IR layer profoundly impacts the orientations of nucleating TMDs domains and, thus, affects the materials' properties. These findings provide deeper insights into the buried interface that could have profound implications for the development of TMD-based electronics and optoelectronics.