Lithium‐ion capacitors (LICs) are hybrid energy storage devices that have the potential to bridge the gap between conventional high‐energy lithium‐ion batteries and high‐power capacitors by combining their complementary features. The challenge for LICs has been to improve the energy storage at high charge−discharge rates by circumventing the discrepancy in kinetics between the intercalation anode and capacitive cathode. In this article, the rational design of new nanostructured LIC electrodes that both exhibit a dominating capacitive mechanism (both double layer and pseudocapacitive) with a diminished intercalation process, is reported. Specifically, the electrodes are a 3D interconnected TiC nanoparticle chain anode, synthesized by carbothermal conversion of graphene/TiO2 hybrid aerogels, and a pyridine‐derived hierarchical porous nitrogen‐doped carbon (PHPNC) cathode. Electrochemical properties of both electrodes are thoroughly characterized which demonstrate their outstanding high‐rate capabilities. The fully assembled PHPNC//TiC LIC device delivers an energy density of 101.5 Wh kg−1 and a power density of 67.5 kW kg−1 (achieved at 23.4 Wh kg−1), and a reasonably good cycle stability (≈82% retention after 5000 cycles) within the voltage range of 0.0−4.5 V.

The rational design and synthesis of nonprecious, efficient, and stable electrocatalysts to replace precious noble metals are crucial to the future of hydrogen economy. Herein, a partial sulfurization/phosphorization strategy is proposed to synthesize a nonstoichiometric pyrrhotite-type cobalt monophosphosulfide material (CoSP) with a hexagonal close-packed phase for electrocatalytic water splitting. By regulating the degree of sulfurization, the P/S atomic ratio in the cobalt monophosphosulfide can be tuned to activate the Co/Co couples. The synergy between the nonstoichiometric nature and the tunable P/S ratio results in the strengthened Co/Co couples and tunable electronic structure and thus efficiently promotes the oxygen/hydrogen evolution reaction (OER/HER) processes toward overall water splitting. Especially for OER, the CoSP material, featured with a uniform yolk-shell spherical morphology, shows a low overpotential of 266 mV at 10 mA cm (η) with a low Tafel slope of 48 mV dec as well as high stability, which is comparable to that of the reported promising OER electrocatalysts. Coupled with the high HER activity of CoSP, the overall water splitting is demonstrated with a low η at 1.59 V and good stability. This study shows that phase engineering and composition control can be the elegant strategy to realize the Co/Co couple activation and electronic structure tuning to promote the electrocatalytic process. The proposed strategy and approaches allow the rational design and synthesis of transition metal monophosphosulfides toward advanced electrochemical applications.

A search for massive coloured resonances which are pair-produced and decay into two jets is presented. The analysis uses 36.7 fb −1 of √ s = 13 TeV pp collision data recorded by the ATLAS experiment at the LHC in 2015 and 2016. No significant deviation from the background prediction is observed. Results are interpreted in a SUSY simplified model where the lightest supersymmetric particle is the top squark,t, which decays promptly into two quarks through Rparity-violating couplings. Top squarks with masses in the range 100 GeV < mt < 410 GeV are excluded at 95% confidence level. If the decay is into a b-quark and a light quark, a dedicated selection requiring two b-tags is used to exclude masses in the ranges 100 GeV < mt < 470 GeV and 480 GeV < mt < 610 GeV. Additional limits are set on the pair-production of massive colour-octet resonances. IntroductionMassive coloured particles decaying into quarks and gluons are predicted in several extensions of the Standard Model (SM). At hadron colliders, the search for new phenomena in fully hadronic final states, without missing transverse momentum, is experimentally challenging due to the very large SM multijet production cross-section. This paper describes a search for pair-produced particles each decaying into two jets using 36.7 fb −1 of √ s = 13 TeV proton-proton ( pp) collision data recorded in 2015 and 2016 by the ATLAS experiment at the Large Hadron Collider (LHC).Supersymmetry (SUSY) [1][2][3][4][5][6][7] is a generalisation of the Poincaré symmetry group that relates fermionic and bosonic degrees of freedom. In the generic superpotential, Yukawa couplings can lead to baryon-and lepton-number violation:where i, j, and k are quark and lepton generation indices. The L i and Q i represent the lepton and quark SU(2) L doublet superfields and H u the Higgs superfield that couples to e-mail: atlas.publications@cern.ch up-type quarks. TheĒ i ,D i , andŪ i are the lepton, downtype quark and up-type quark SU(2) L singlet superfields, respectively. For each term the couplings are λ, λ , λ , as well as κ which is a dimensional mass parameter. The λ and λ couplings are antisymmetric in the exchange of i → j and j → k, respectively. While these terms in many scenarios are removed by imposing an additional Z 2 symmetry (R-parity) [8], the possibility that at least some of these Rparity-violating (RPV) couplings are not zero is not ruled out experimentally [9,10]. This family of models leads to unique collider signatures which can escape conventional searches for R-parity-conserving SUSY.Naturalness arguments [11,12] suggest that higgsinos and top squarks 1 (stops) should be light, with masses below a TeV [13,14]. Third-generation squarks in R-parityconserving scenarios, and top squarks in particular, have been the subject of a thorough programme of searches at the LHC [15][16][17][18][19][20][21][22].If the top squark decays through RPV couplings, however, the existing bounds on its mass can be significantly relaxed [23][24][25][26]. Indirect experimental constrain...

Reduced graphene oxide (RGO) has proved to be a promising candidate in high‐performance gas sensing in ambient conditions. However, trace detection of different kinds of gases with simultaneously high sensitivity and selectivity is challenging. Here, a chemiresistor‐type sensor based on 3D sulfonated RGO hydrogel (S‐RGOH) is reported, which can detect a variety of important gases with high sensitivity, boosted selectivity, fast response, and good reversibility. The NaHSO3 functionalized RGOH displays remarkable 118.6 and 58.9 times higher responses to NO2 and NH3, respectively, compared with its unmodified RGOH counterpart. In addition, the S‐RGOH sensor is highly responsive to volatile organic compounds. More importantly, the characteristic patterns on the linearly fitted response–temperature curves are employed to distinguish various gases for the first time. The temperature of the sensor is elevated rapidly by an imbedded microheater with little power consumption. The 3D S‐RGOH is characterized and the sensing mechanisms are proposed. This work gains new insights into boosting the sensitivity of detecting various gases by combining chemical modification and 3D structural engineering of RGO, and improving the selectivity of gas sensing by employing temperature dependent response characteristics of RGO for different gases.

A facile and bottom-up approach has been presented to prepare 2D Ni-MOFs based on cyanide-bridged hybrid coordination polymers. After thermally induced sulfurization and selenization processes, Ni-MOFs were successfully converted into NiS and NiSe2 nanoplates with carbon coating due to the decomposition of its organic parts. When evaluated as anodes of Li-ion batteries (LIBs) and Na-ion batteries (NIBs), NiS and NiSe2 nanoplates show high specific capacities, excellent rate capabilities, and stable cycling stability. The NiS plates show good Li storage properties, while NiSe2 plates show good Na storage properties as anode materials. The study of the diffusivity of Li(+) in NiS and Na(+) in NiSe2 shows consistent results with their Li/Na storage properties. The 2D MOFs-derived NiS and NiSe2 nanoplates reported in this work explore a new approach for the large-scale synthesis of 2D metal sulfides or selenides with potential applications for advanced energy storage.