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Abstract The monitoring of currents in the abyssal ocean is an essential foundation of deep-sea research. The state-of-the-art current meter has limitations such as the requirement of a power supply for signal transduction, low pressure resistance, and a narrow measurement range. Here, we report a fully integrated, self-powered, highly sensitive deep-sea current measurement system in which the ultra-sensitive triboelectric nanogenerator harvests ocean current energy for the self-powered sensing of tiny current motions down to 0.02 m/s. Through an unconventional magnetic coupling structure, the system withstands immense hydrostatic pressure exceeding 45 MPa. A variable-spacing structure broadens the measuring range to 0.02–6.69 m/s, which is 67% wider than that of commercial alternatives. The system successfully operates at a depth of 4531 m in the South China Sea, demonstrating the record-deep operations of triboelectric nanogenerator-based sensors in deep-sea environments. Our results show promise for sustainable ocean current monitoring with higher spatiotemporal resolution.

While H2 evolution from water may represent a renewable energy source, there is a strong need to improve catalytic efficiencies while maximizing materials utilization. Here, authors examine single-atom Pt on nickel-based heterostructures as highly active electrocatalysts for alkaline H2 evolution.

Abstract Catalytically active metals atomically dispersed on supports presents the ultimate atom utilization efficiency and cost‐effective pathway for electrocatalyst design. Optimizing the coordination nature of metal atoms represents the advanced strategy for enhancing the catalytic activity and the selectivity of single‐atom catalysts (SACs). Here, we designed a transition‐metal based sulfide‐Ni3S2 with abundant exposed Ni vacancies created by the interaction between chloride ions and the functional groups on the surface of Ni3S2 for the anchoring of atomically dispersed Pt (PtSA‐Ni3S2). The theoretical calculation reveals that unique Pt‐Ni3S2 support interaction increases the d orbital electron occupation at the Fermi level and leads to a shift‐down of the d ‐band center, which energetically enhances H2O adsorption and provides the optimum H binding sites. Introducing Pt into Ni position in Ni3S2 system can efficiently enhance electronic field distribution and construct a metallic‐state feature on the Pt sites by the orbital hybridization between S‐3p and Pt‐5d for improved reaction kinetics. Finally, the fabricated PtSA‐Ni3S2 SAC is supported by Ag nanowires network to construct a seamless conductive three‐dimensional (3D) nanostructure (PtSA‐Ni3S2@Ag NWs), and the developed catalyst shows an extremely great mass activity of 7.6 A mg−1 with 27‐time higher than the commercial Pt/C HER catalyst.

Organic–inorganic perovskite single crystals are promising in the field of optoelectronics due to their excellent optoelectronic properties. However, the ion transport of perovskite precursor is poor in confined spaces, which results in difficulty in the preparation of perovskite single-crystal films. Herein, MAPbBr3 films consisting of square grains were fabricated by the surface-confined process using the organic molecule PEAI (phenethylammonium iodide). Under the effect of oversaturation gradient, PEA+ is combined with the surface of perovskite grain from top to side, which constrains the lateral growth of grains and induces a downward growth of perovskite, leading to the formation of square grains. With the improvement of concentration PEAI, the perovskite film exhibits a decreased side length of grains (from 0.98 to 12.96 μm) and increased grain number and coverage, as well as crystallinity. The perovskite single crystalline grain films with PEAI showed double photoluminescence (PL) emission peaks due to the existence of iodine-rich perovskite. This work may provide a practical way to fabricate high-quality perovskite films for perovskite photoelectronic devices.

Equipment used in underwater sensing and exploration typically relies on cables or batteries for energy supply, resulting in a limited and inconvenient energy supply and marine environmental pollution that hinder the sustainable development of distributed ocean sensing networks. Here, we design a deep-sea differential-pressure triboelectric nanogenerator (DP-TENG) based on a spiral shaft drive using modified polymer materials to harness the hydrostatic pressure gradient energy at varying ocean depths to power underwater equipment. The spiral shaft structure converts a single compression into multiple rotations of the TENG rotor, achieving efficient conversion of differential pressure energy. The multi-pair electrode design enables the DP-TENG to generate a peak current of 61.7 μA, the instantaneous current density can reach 0.69 μA cm-2, and the output performance can be improved by optimizing the spiral angle of the shaft. The DP-TENG can charge a 33 μF capacitor to 17.5 V within five working cycles. It can also power a digital calculator and light up 116 commercial power light-emitting diodes, demonstrating excellent output capability. With its simple structure, low production cost, and small form factor, the DP-TENG can be seamlessly integrated with underwater vehicles. The results hold broad prospects for underwater blue energy harvesting and are expected to contribute to the development of self-powered equipment toward emerging “smart ocean” and blue economy applications. [ABSTRACT FROM AUTHOR]

A ball-bearing structure based triboelectric nanogenerator (B-TENG) with interdigitative-electrodes was developed that can not only collect energy from rotational kinetic energy, but also serve as a self-powered and multifunctional sensor. The B-TENG relies on the rolling electrification between PTFE balls on Cu interdigitative-electrodes, which delivers an open-circuit voltage of ∼40 V and a short-circuit current of ∼1.2 μA at a rotating speed of 300 rpm for 4 mm PTFE balls. Using the output signals of B-TENG, a nondestructive detection for the damage of PTFE balls was realized without demounting the bearing. Besides, based on the periodic signals produced from B-TENG, the rotation speed of ball-bearing can be obtained according to the time difference between several cycles. [ABSTRACT FROM AUTHOR]