Thermally annealing mixtures of MoS2 and red phosphorus from 1:0.5 to 1:8 w:w ratio at 750 °C for 1 h under argon/hydrogen leads to the formation of a MoS2(1−x)Px solid solution (x = 0 to 1). At x = 0.53, the solid solution possesses one of the highest hydrogen evolution reaction (HER) activities of non-precious-metal-based electrocatalysts. The effective and stable electrocatalyst for hydrogen evolution in acidic solution developed here holds promise for substitution of scarce and expensive platinum. The high performance originates from the increased surface area and roughness of the solid solution, as well as the activation of the previously non-active sites as suggested by first–principles calculations. The enhanced HER activity via formation of a hetero-anion solid solution may open a new avenue for improving performance of HER and related electrocatalysts.
Hybrid materials incorporating the advantages of graphene and nanoparticles have been widely studied. Here we develop an improved cost-effective approach for preparation of porous graphene embedded with various types of nanoparticles. Direct laser scribing on metal-complex-containing polyimide film leads to in situ formation of nanoparticles embedded in porous graphene. These materials are highly active in electrochemical oxygen reduction reactions, converting O2 into OH(-), with a low metal loading of less than 1 at. %. In addition, the nanoparticles can vary from metal oxide to metal dichalcogenides through lateral doping, making the composite active in other electrocatalytic reactions such as hydrogen evolution.
An automated metal powder three-dimensional (3D) printing method for in situ synthesis of free-standing 3D graphene foams (GFs) was successfully modeled by manually placing a mixture of Ni and sucrose onto a platform and then using a commercial CO laser to convert the Ni/sucrose mixture into 3D GFs. The sucrose acted as the solid carbon source for graphene, and the sintered Ni metal acted as the catalyst and template for graphene growth. This simple and efficient method combines powder metallurgy templating with 3D printing techniques and enables direct in situ 3D printing of GFs with no high-temperature furnace or lengthy growth process required. The 3D printed GFs show high-porosity (∼99.3%), low-density (∼0.015g cm), high-quality, and multilayered graphene features. The GFs have an electrical conductivity of ∼8.7 S cm, a remarkable storage modulus of ∼11 kPa, and a high damping capacity of ∼0.06. These excellent physical properties of 3D printed GFs indicate potential applications in fields requiring rapid design and manufacturing of 3D carbon materials, for example, energy storage devices, damping materials, and sound absorption.
Anti-icing and deicing are the two major pathways for suppressing adhesion of ice on surfaces, yet materials with dual capabilities are rare. In this work, we have designed a perfluorododecylated graphene nanoribbon (FDO-GNR) film that takes advantage of both the low polarizability of perfluorinated carbons and the intrinsic conductive nature of graphene nanoribbons. The FDO-GNR films are superhydrophobic with a sheet resistance below 8 kΩ·sq(-1) and then exhibit an anti-icing property that prevents freezing of incoming ice-cold water down to -14 °C. After that point, voltage can be applied to the films to resistively heat and deice the surface. Further a lubricating liquid can be employed to create a slippery surface to improve the film's deicing performance. The FDO-GNR films can be easily switched between the superhydrophobic anti-icing mode and the slippery deicing mode by applying the lubricant. A spray-coating method makes it suitable for large-scale applications. The anti-icing and deicing properties render the FDO-GNR films with promise for use in extreme environments.
The hybridization of graphene with other inorganic nanostructures has endowed graphene with enhanced and varied functionalities. Here we demonstrate a facile and improved approach to convert biodegradable cedar wood into graphene embedded with various metal nanocrystals (cedar-LIG-M, LIG is laser-induced graphene, M = Cu, Co, Ni, Fe, NiFe) by sonication-assisted soaking and one-step CO2 laser scribing. Organic biomass was transformed to hierarchical porous graphene via laser induction, whereas metal salts were reduced to elemental metals simultaneously by the carbothermal reaction and reducing atmosphere generated during the lignocellulose decomposition. The as-prepared cedar-LIG-M possesses an ordered porous structure, good conductivity, unique ferromagnetic behavior and excellent electrochemical catalytic performance. As a demonstration, the cedar-LIG-NiFe electrode has a low overpotential of 296 mV at a current density of 10 mA cm–2 for oxygen evolution reactions. The performance of the electrode continued to improve at the initial testing stage due to the in situ activation as a result of the increased oxidation states of nickel and iron during electrochemical oxygen evolution. In addition, the cedar-LIG-NiFe could also serve as an electromagnetic interference shielding material with shielding effectiveness up to 54 dB. The simplicity and versatility of this technique provides a route for the synthesis of various carbon-based hybrid materials with potential applications of the products in many different fields, such as energy storage, electrocatalysis, electromagnetic interference shielding, and water treatment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.