Pt Edge-Doped MoS2 : Activating the Active Sites for Maximized Hydrogen Evolution Reaction Performance.

The demand of clean energy calls for efficient and low-cost hydrogen evolution reaction electrocatalysts. Fabricating hybrid catalysts from noble/non-noble catalysts is a practical route to reducing the consumption of noble metals and enhancing catalytic efficiency. Here, 2H-MoS2 is etched and edge-doped with Pt nanoparticles using focused ion beam and photoreduction techniques. Precise comparison of as-prepared samples demonstrates that the enhancement of catalytic performance can be controlled through tuning the catalyst defect length. On this basis, remarkably high performance is obtained by designing a specific defect array that is superior to commercial Pt/C with less Pt loading and higher mass activity. It has been proved by experimentation and COMSOL Multiphysics simulations that the promotion of catalytic activity not only benefits from the synergistic effect of Pt and edge active sites, but also contributes to the increased potential at the edges of the designed defect. This study sheds light on the mechanism of understanding nanoscale edge-doped hybrid catalysts and provides a feasible strategy for the full utilization of noble metals.

Plant Transpiration-Inspired Biomass-Based Device with Underwater Oleophobicity for Efficient General-Purpose Solar-Driven Oily Wastewater Purification.

The remediation of wastewater containing oily pollutants is imperative to mitigate the serious threats posed to the safety of fresh water, human well-being, and the environment. Current membrane separation technologies are severely restricted by their limitations for separating various types of oily pollutants with low sustainability. Herein, by imitating the plant transpiration in nature, we designed a solar-driven device composed of natural biomass sugar cane stem, chitosan/carboxymethyl cellulose, and graphite powders to separate versatile oily pollutants from the wastewater. Owing to its superior solar absorption capacity, microchannels for water transportation, and underwater oleophobicity, the resultant evaporator not only exhibited an excellent evaporation rate of 1.41 kg m-2 h-1 but also demonstrated an admirable purification efficiency of 99.9% for oily wastewater. Moreover, the device can maintain a stable evaporation rate and the original structure even in oily wastewater containing strong acid, alkali, or hypersaline components. Therefore, this work provides an effective approach to producing clean water from versatile wastewater.