Mercury pollution threatens the environment and human health across the globe. This neurotoxic substance is encountered in artisanal gold mining, coal combustion, oil and gas refining, waste incineration, chloralkali plant operation, metallurgy, and areas of agriculture in which mercury‐rich fungicides are used. Thousands of tonnes of mercury are emitted annually through these activities. With the Minamata Convention on Mercury entering force this year, increasing regulation of mercury pollution is imminent. It is therefore critical to provide inexpensive and scalable mercury sorbents. The research herein addresses this need by introducing low‐cost mercury sorbents made solely from sulfur and unsaturated cooking oils. A porous version of the polymer was prepared by simply synthesising the polymer in the presence of a sodium chloride porogen. The resulting material is a rubber that captures liquid mercury metal, mercury vapour, inorganic mercury bound to organic matter, and highly toxic alkylmercury compounds. Mercury removal from air, water and soil was demonstrated. Because sulfur is a by‐product of petroleum refining and spent cooking oils from the food industry are suitable starting materials, these mercury‐capturing polymers can be synthesised entirely from waste and supplied on multi‐kilogram scales. This study is therefore an advance in waste valorisation and environmental chemistry.

Graphene has emerged as a material with a vast variety of applications. The electronic, optical and mechanical properties of graphene are strongly influenced by the number of layers present in a sample. As a result, the dimensional characterization of graphene films is crucial, especially with the continued development of new synthesis methods and applications. A number of techniques exist to determine the thickness of graphene films including optical contrast, Raman scattering and scanning probe microscopy techniques. Atomic force microscopy (AFM), in particular, is used extensively since it provides three-dimensional images that enable the measurement of the lateral dimensions of graphene films as well as the thickness, and by extension the number of layers present. However, in the literature AFM has proven to be inaccurate with a wide range of measured values for single layer graphene thickness reported (between 0.4 and 1.7 nm). This discrepancy has been attributed to tip-surface interactions, image feedback settings and surface chemistry. In this work, we use standard and carbon nanotube modified AFM probes and a relatively new AFM imaging mode known as PeakForce tapping mode to establish a protocol that will allow users to accurately determine the thickness of graphene films. In particular, the error in measuring the first layer is reduced from 0.1-1.3 nm to 0.1-0.3 nm. Furthermore, in the process we establish that the graphene-substrate adsorbate layer and imaging force, in particular the pressure the tip exerts on the surface, are crucial components in the accurate measurement of graphene using AFM. These findings can be applied to other 2D materials.

A polysulfide material was synthesized by the direct reaction of sulfur and d‐limonene, by‐products of the petroleum and citrus industries, respectively. The resulting material was processed into functional coatings or molded into solid devices for the removal of palladium and mercury salts from water and soil. The binding of mercury(II) to the sulfur‐limonene polysulfide resulted in a color change. These properties motivate application in next‐generation environmental remediation and mercury sensing.

This is because chlorine evolution takes place at the counter electrode and highly corrosive hypochlorite by-products block the active sites of the noble metal catalysts. [6,13,18] Consequently, development of stable and active electrocatalysts for seawater splitting is of crucial importance for this process. Transition metal nitrides (TMNs) have excellent electrical conductivity and corrosion resistance and have demonstrated good stability for seawater splitting. [18-20] However, most of the bulk TMNs reported exhibit unsatisfactory HER activity due to a suboptimal hydrogen bonding energy. [21,22] Consequently, material optimization strategies, such as vacancy engineering, alloying, interface engineering, and heteroatom doping are usually needed to improve their activity. [23-28] For example, interfacing MoN with C 3 N 4 can greatly promote HER activity in alkaline media. [29] Tungsten and phosphorus doping in Co 3 N can manipulate the dehydrogenation kinetics and increase hydrogen production. [27] Despite significant investigation into TMNs, adequate activity and corrosion resistance are still required to be achieved simultaneously, and more advanced modification methods need to be developed. Manipulating the stoichiometry is one such way to optimize the properties of TMNs. Using this strategy, the N atom ratio in the metal matrix can be tuned to regulate the TMN electronic structure. [18,24,25,30] The two main approaches to controlling the nitrogen content in TMNs are the nitrogen-rich process and the incomplete nitridation process. [31-33] The nitrogen-rich process aims to embed extra nitrogen atoms into the TMN lattice but usually requires high-temperature and high-pressure conditions due to sluggish thermodynamics. [30,31,34,35] The incomplete nitridation process can limit the metal-nitrogen bonding in the matrix and promote the formation of metal/ metal nitride interfaces, which generally offers better conductivity and subsequent electrocatalytic activity. [23,25,33,36] However, the stoichiometry in a metal/metal nitride heterostructure is difficult to control and deficient or superfluous nitridation can lead to poor electrocatalytic activity. Herein, we synthesized a nickel surface nitride encapsulated in a carbon shell (Ni-SN@C) using an unsaturated nitriding process. Compared to conventional TMNs or metal/metal nitride heterostructures, the unsaturated Ni-SN@C has no detectable bulk nickel nitride phase. Instead, the main chemical composition of Ni-SN@C is metallic Ni but with unique Electrocatalytic production of hydrogen from seawater provides a route to low-cost and clean energy conversion. However, the hydrogen evolution reaction (HER) using seawater is greatly hindered by the lack of active and stable catalysts. Herein, an unsaturated nickel surface nitride (Ni-SN@C) catalyst that is active and stable for the HER in alkaline seawater is prepared. It achieves a low overpotential of 23 mV at a current density of 10 mA cm −2 in alkaline seawater electrolyte, which is superior to Pt/C. Compared to conv...

Lithium-sulfur batteries hold promise for nextgeneration batteries.Aproblem, however,i sr apid capacity fading. Moreover,a tomic-level understanding of the chemical interaction between sulfur host and polysulfides is poorly elucidated from at heoretical perspective.H ere,atwo-dimensional (2D) heterostructured MoN-VN is fabricated and investigated as an ew model sulfur host. Theoretical calculations indicate that electronic structure of MoN can be tailored by incorporation of V. This leads to enhanced polysulfides adsorption. Additionally,insitu synchrotron X-raydiffraction and electrochemical measurements reveal effective regulation and utilization of the polysulfides in the MoN-VN.The MoN-VN-based lithium-sulfur batteries have ac apacity of 708 mA hg À1 at 2Cand ac apacity decay as low as 0.068 % per cycle during 500 cycles with sulfur loading of 3.0 mg cm À2 .Compared with lithium-ion batteries,l ithium-sulfur batteries are both low-cost and low-contamination and have ahigh theoretical specific capacity of % 1675 mA hg À1 . [1] However, the solubility of the intermediate lithium polysulfides (LiPoSs) results in low Columbic efficiency and rapid capacity fading. [2] Moreover,t he atomic-level LiPoSs adsorption behaviour on sulfur hosts are difficult to study because of al ack of theoretical guidance.T his significantly impedes design and development of efficient sulfur hosts. [3] Thes urface and interface engineering of inorganic materials to construct heterostructured sulfur hosts has received significant attention in lithium-sulfur batteries. [4] This can achieve regulation of LiPoSs via enhancing LiPoSs chemical adsorption and improving their surface redox kinetics on the heterostructured sulfur hosts,l eading to increased charge/discharge capacity and cycling stability of lithium-sulfur batteries. [5] More importantly,L iPoSs adsorption ability on the heterostructured sulfur hosts can be further improved because of the novel physicochemical properties at interfaces offered by the interfacial effect. [3a] This plays an essential role in further regulating LiPoSs and therefore improving the performance of sulfur hosts in lithium-sulfur batteries.However,origin of the LiPoSs adsorption enhancement has been poorly elucidated due to alack of atomic-level understanding of LiPoSs adsorption behaviour on the heterostructured sulfur hosts. [6] Owing to their uniformly exposed crystal lattices,t wodimensional (2D) sulfur host materials can serve as an ideal model in density functional theory (DFT) computationswhich deals mainly with LiPoSs adsorption energies and adsorption sites identification. [7] More importantly,D FT computations can calculate electronic structures of the sulfur hosts and reveal their adsorption origin. These therefore play ak ey role in gaining atomic-level understanding of LiPoSs adsorption behaviour and exploring suitable sulfur host materials for high-performance lithium-sulfur batteries. [8] To date,D FT computations of various 2D one-component inorganic sulfur host materials,i ncluding laye...