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Various exciton species in transition metal dichalcogenides (TMDs), such as neutral excitons, trions (charged excitons), dark excitons, and biexcitons, have been individually discovered with distinct light-matter interactions. In terms of valley-spin locked band structures and electron-hole configurations, these exciton species demonstrate flexible control of emission light with degrees of freedom (DOFs) such as intensity, polarization, frequency, and dynamics. However, it remains elusive to fully manipulate different exciton species on demand for practical photonic applications. Here, we investigate the contrasting light-matter interactions to control multiple DOFs of emission light in a hybrid monolayer WSe2-Ag nanowire (NW) structure by taking advantage of various exciton species. These excitons, including trions, dark excitons, and biexcitons, are found to couple independently with propagating surface plasmon polaritons (SPPs) of Ag NW in quite different ways, thanks to the orientations of transition dipoles. Consistent with the simulations, the dark excitons and dark trions show extremely high coupling efficiency with SPPs, while the trions demonstrate directional chiral-coupling features. This study presents a crucial step towards the ultimate goal of exploiting the comprehensive spectrum of TMD excitons for optical information processing and quantum optics.

In this experiment, graphite phase carbon nitride (g-C3N4) has been use as a photocatalyst to study the problems of small specific surface area and low visible light efficiency. Firstly, the graphene oxide (GO) and reduced graphene oxide (rGO) were respectively synthesized with g-C3N4 in a certain proportion by ultrasonic assisted synthesis method. And the composites were characterized and analyzed by XRD, SEM, FT-R, XPS, UV-Vss and other characterization methods. Secondly, the photocatalytic degradation and kinetics of rhodamine B (RhB) under simulated sunlight were studied. Finally, the experimental results show that the GO/CN and rGO/CN composter photocatalysts have the same phase structure and more porous morphology as g-C3N4, and the graphene composter material can improve the visible light absorption capacity of g-C3N4, and reduce its band gap width. Also, according to the analysis of visible right photocatalytic performance, rGO/CN2 has stronger adsorption capacity, and the adsorption rate f RhB at 30 min up to 64.79%, 5.2 times that of g-C3N4 under the same conditions. GO/CN1.5 shows excellent photocatalytic activity, and its catalytic reaction rate constant is 9.108 X 10-2/min. When RhB ss degraded for 10 min, the degradation rate reaches 86.34%, which is 1.5 times that of g-C3N4 under the same conditions. [ABSTRACT FROM AUTHOR]

Hydrogen oxidation reaction (HOR) as the anode reaction in proton exchange membrane fuel cell, usually suffers from the high loading of platinum (Pt) and subsequent CO poisoning especially by using industrial crude hydrogen as fuel. In this work, we propose a directional electron transfer route from Pt to MoO 2- x in the macroporous structure to significantly enhance the HOR activity as well as the CO tolerance, which is constructed by interface engineering and defect strategy to anchor highly dispersed Pt nanoparticles onto the three-dimensional MoO 2- -C with 1.02 wt% Pt demonstrates higher HOR peak current density (3.57 mA cm x -C framework. The optimized 2Pt-MoO 2- x -C with 1.02 wt% Pt demonstrates higher HOR peak current density (3.57 mA cm -2 ) and nearly 25 times higher mass activity than 20 wt% Pt/C. The excellent HOR performance is attributed to the synergistic effect between Pt and MoO 2- x species, in which the charge transfer from Pt to MoO 2- x improves H 2 adsorption ability of Pt and accelerates the activation of H 2 due to the reduced hydrogen binding energy of MoO 2- x caused by Pt-O construction, leading to the release of H* thereby the enhancement of HOR activity. The construction of three-dimensional macroporous structure enhances the HOR dynamics by promoting the conductivity, mass transfer and the exposure of active sites. Moreover, the formed Mo-OH in Pt-MoO 2- x -C can effectively react with CO species to remove the CO poisoning of Pt, endowing the excellent CO tolerance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In recent decades, environmental protection and energy issues have gained significant attention, and the development of efficient, environmentally friendly catalysts has become especially crucial for the advancement of photocatalytic technology. This study employs the sintering method to produce biochar. A hybrid photocatalyst for the degradation of RHB under visible light was prepared by loading varying proportions of biochar onto g-C 3 N 4 using ultrasonic technology. Among them, 2% CGCD (2% biochar/g-C 3 N 4 ) achieved a degradation rate of 91.3% for RHB after 30 minutes of visible light exposure, which was more than 25% higher than GCD (g-C 3 N 4 ), and exhibited a higher photocurrent intensity and lower impedance value. The enhancement in photocatalytic activity is primarily attributed to the increased utilization efficiency of visible light and the electron transfer channel effect from a minor amount of biochar, effectively reducing the recombination of photo-generated charge carriers on the g-C 3 N 4 surface, thereby significantly improving photocatalytic activity. The degradation of RHB is synergistically mediated by O 2 - , h + (photo-generated holes), and ˙OH. The free radical capture experiment indicates that O 2 - and ˙OH are the primary active components, followed by h + ., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)