Energy-distributable waterborne acoustic launcher for directional sensing

Highly directional launch and intensity adjustment of underwater acoustic signals are crucial in many areas such as abyssal navigation,underwater signal communication,and detection for marine biology.Inspired by the phenomenon that aquatic animals like dolphins detect and track prey with high resolution,we propose an energy-distributable directional sensing strategy which can achieve parallel needle-like transmitting sound beams with adjustable energy based on out-coupling valley-polarized edge states.The acoustic spin angular momentum and energy flow distribution at different interfaces inside the phononic crystal are provided and they show tight coupling.Furthermore,a sound beam with a width of 20°and an acoustic intensity enhancement factor≈6.6 are observed in the far field.As an application,we show that this device can be used as an acoustic energy distributor.This communication pattern with excellent functionalities and performance provides a desirable idea for high-energy-level directional collimated underwater sensing and underwater acoustic energy distribution.

Synergistic effect of heterogeneous single atoms and clusters for improved catalytic performance

Electrocatalytic water splitting provides an efficient method for the production of hydrogen.In electrocatalytic water splitting,the oxygen evolution reaction(OER)involves a kinetically sluggish four-electron transfer process,which limits the efficiency of electrocatalytic water splitting.Therefore,it is urgent to develop highly active OER catalysts to accelerate reaction kinetics.Coupling single atoms and clusters in one system is an innovative approach for developing efficient catalysts that can synergistically optimize the adsorption and configuration of intermediates and improve catalytic activity.However,research in this area is still scarce.Herein,we constructed a heterogeneous single-atom cluster system by anchoring Ir single atoms and Co clusters on the surface of Ni(OH)_(2)nanosheets.Ir single atoms and Co clusters synergistically improved the catalytic activity toward the OER.Specifically,Co_(n)Ir_(1)/Ni(OH)_(2)required an overpotential of 255 mV at a current density of 10 mA·cm^(−2),which was 60 mV and 67 mV lower than those of Co_(n)/Ni(OH)_(2)and Ir1/Ni(OH)_(2),respectively.The turnover frequency of Co_(n)Ir_(1)/Ni(OH)_(2)was 0.49 s^(−1),which was 4.9 times greater than that of Co_(n)/Ni(OH)_(2)at an overpotential of 300 mV.