In Situ Synthesis of Efficient Water Oxidation Catalysts in Laser-Induced Graphene

Abstract

NiFe-based catalysts are highly active for the oxygen evolution reaction (OER) in alkaline electrolytes. These catalysts are generally synthesized by solution-based methods. We present an in situ synthesis method for NiFe-based OER catalysts through a laserinduced graphene (LIG)-assisted process. By loading the metal precursor on a preformed LIG surface followed by laser scribing, we synthesized the NiFe/LIG catalysts via a solid phase transition that did not require utilization of CVD or typical solution-based reactions. The catalysts showed high OER activity and durability. The overpotential at 10 mA cm −2 is as low as 240 mV with a Tafel slope of 32.8 mV dec −1 in 1 M KOH. Additionally, this method worked well on a carbon fiber paper substrate, providing a convenient approach for the preparation of a free-standing catalytic electrode. This method provides a potential route to the facile synthesis of a variety of catalysts on a conductive surface.

ZnO decorated laser-induced graphene produced by direct laser scribing

“…48 Moreover, its application extend from microuidic devices, sensors, optoelectronic devices, microsupercapacitors, to catalysts, among others. 40,41,43,45,46,49 When compared to other techniques, the method in focus by the present report possesses key advantages. Among these, we highlight the prompt synthesis process of the composites, the ability to perform a pattern with the computer-controlled laserscribing system, the production of exible composite's samples and its easy scalability in a time-and cost-effective way.…”

Laser‐Induced Graphene: From Discovery to Translation

“…A higher performance was reported by Zhang et al on NiFe and PI‐derived LIG composite, which reduced the overpotential to 240 mV and improved the Tafel slope to 32.8 eV dec −1 . All of the NiFe‐LIG electrodes showed excellent durability in OER …”

A Highly Stretchable Microsupercapacitor Using Laser‐Induced Graphene/NiO/Co3O4 Electrodes on a Biodegradable Waterborne Polyurethane Substrate

“…[12,15] While in situ synthesized NiO/Co 3 O 4 /LIG shows a completely different morphology (Figure 1d) in that the entire structure is composed of multilayer graphene, which is a synergistic result of the simultaneous carbonization of PI and gelatin. [43,44] Moreover, the water contact angles ( Figure S2, Supporting Information) clearly reveal that the gelatin ion ink is a key factor in converting the hydrophilic pristine LIG (114.5° ± 2.3°) into hydrophobic (22.1° ± 0.8°) NiO/Co 3 O 4 /LIG, which is well suited for the penetration of WPU. [35] These hybrid NiO/Co 3 O 4 catalysts help maintain a high surface area, allowing the electrolyte to sufficiently interact with the entire surface of the electrode, which in turn facilitates ion transport during redox reactions.…”