Tetrahexahedral Pt nanocrystals (THH Pt NCs) bound by well-defined high index crystal planes offer exceptional electrocatalytic activity, owing to a high density of low-coordination surface Pt sites. We report, herein, on methanol electrooxidation at THH Pt NC electrodes studied by a combination of electrochemical techniques and in situ FTIR spectroscopy. Pure THH Pt NC surfaces readily facilitate the dissociative chemisorption of methanol leading to poisoning by strongly adsorbed CO. Decoration of the stepped surfaces by Ru adatoms increases the tolerance to poisoning and thereby reduces the onset potential for methanol oxidation by over 100 mV. The Ru modified THH Pt NCs exhibit greatly superior catalytic currents and CO2 yields in the low potential range, when compared with a commercial PtRu alloy nanoparticle catalyst. These results are of fundamental importance in terms of model nanoparticle electrocatalytic systems of stepped surfaces and also have practical significance in the development of surface tailored, direct methanol fuel cell catalysts.NSFC [21021002, 20933004, 21073152, 20873113]; Fundamental Research Funds for the Central Universities [2010121021]; Program for New Century Excellent Talents in University; Queen's University Belfast (The ISW DEL Clean Energies); EPSRC [EP/I013229/1

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An updated mode of the thermoradiative cell (TRC) with sub-band gap and non-radiative losses is proposed, which can efficiently harvest moderate-temperature heat energy and convert a part of heat into electricity. It is found that when the TRC is operated between the heat source at 800 K and the environment at 300 K, its maximum power output density and efficiency can attain 1490 W m−2 and 27.2%, respectively. Moreover, the effects of some key parameters including the band gap and voltage output on the performance of the TRC are discussed. The optimally working regions of the power density, efficiency, band gap, and voltage output are determined. The maximum efficiency and power output density of the TRC operated at different temperatures are calculated and compared with those of thermophotovoltaic cells (TPVCs) and thermionic energy converters (TECs), and consequently, it is revealed that the maximum efficiency of the TRC operated at the moderate-temperature range is much higher than that of the TEC or the TPVC and the maximum power output density of the TRC is larger than that of the TEC but smaller than that of the TPVC. Particularly, the TRC is manufactured more easily than the near-field TPVC possessing a nanoscale vacuum gap. The results obtained will be helpful for engineers to choose the semiconductor materials, design and manufacture TRCs, and control operative conditions.

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SnS has been studied widely and deeply as a promising anode material for sodium-ion batteries. However, the large volume expansion, the great structural pulverization, and the slow electronic transmission have been the foremost obstacles to their further applications. Here, Sb2S3@SnS@C nanocomposites with a hollow-tube-heterostructure were constructured to mitigate the above problems. As the anode materials, the Sb2S3@SnS@C nanocomposites can deliver a high capacity of 442 mA h g–1 after 200 cycles at 1 A g–1 and excellent rate capacity of 448 mA h g–1 at 5.0 A g–1. Besides, a capacity of 200 mA h g–1 could be detected with a superior cycling performance of 1300 cycles at 5.0 A g–1. The outstanding cycle stability could be ascribed to the inner hollow tube structure and the protection of the outer carbon layer, which together maintain the stability of the structure jointly. Moreover, the internal electric field generated by the heterojunction of Sb2S3 and SnS promotes the electronic transmission and ion diffusion, resulting in good electrochemical performances.

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