CN-121992442-A - Preparation method of CoO/CoP-LIG heterojunction water electrolysis catalyst

Abstract

The invention provides a preparation method of a CoO/CoP-LIG heterojunction electrolytic water catalyst, belonging to the technical field of preparation methods of electrocatalytic materials. CoO and CoP in the electrocatalytic material are heterostructures, and a large number of active interfaces and defect sites are exposed between the two components, so that the electrocatalytic material is favorable for electrocatalytic reaction. The laser-induced graphene (LIG) has excellent conductivity and huge specific surface area, and provides an ideal platform for the loading of CoO/CoP heterojunction nano-sheets and the construction of electron/mass transfer channels. The electrolyzed water catalyst has the advantages of simple preparation process, high stability, low raw material price and easy realization of industrialized mass production, and is beneficial to realizing the industrialized development of electrolyzed water hydrogen production. The electrolyzed water catalyst can also be applied to the degradation of urea in industrial and agricultural pollutants, and is an environment-friendly electrolyzed water catalyst.

Inventors

• WU KAILI
• GAO YAN
• WANG JIA
• ZHANG XIANGNAN
• JIA WENYAO
• LI YANYING

Assignees

• 山东理工大学

Dates

Publication Date

20260508

Application Date

20260212

Claims (4)

1. 1. The preparation method of the CoO/CoP-LIG heterojunction water electrolysis catalyst is characterized by comprising the following steps of: Step one, regulating and controlling laser energy density, scanning line spacing, processing speed and defocusing distance of a certain size, and laser processing polyimide paper to prepare laser-induced graphene (LIG); Step two, using the LIG as a working electrode, using a saturated Ag/AgCl electrode as a reference electrode, using a Pt sheet as a counter electrode, using a cobalt nitrate hexahydrate solution with a certain concentration as an electrolyte, setting a certain voltage in a three-electrode system, and reacting for a period of time to obtain the LIG with Co (OH) 2 nano sheets grown on the surface; Thirdly, placing LIG with a certain size of Co (OH) 2 nano sheets grown on the surface into a porcelain boat, placing the LIG into the downwind direction of a tube furnace, placing a certain amount of sodium hypophosphite into the porcelain boat positioned in the upwind direction, vacuumizing the tube furnace, introducing argon gas, heating the tube furnace to a certain reaction temperature, preserving heat for a period of time, naturally cooling, and taking out the tube furnace to obtain the CoO/CoP-LIG heterojunction water electrolysis catalyst.
2. 2. The method for preparing the CoO/CoP-LIG heterojunction water electrolysis catalyst according to claim 1, wherein in the first step, the laser energy density is 10-40J/cm 2 , the scanning line spacing is 0.01-0.1 mm, the processing speed is 100-500 mm/s, and the defocusing distance is 0-5 mm.
3. 3. The method for preparing the CoO/CoP-LIG heterojunction water electrolysis catalyst according to claim 1, wherein in the second step, the concentration of the cobalt nitrate hexahydrate solution is 0.05-0.15 mol/L, the voltage is-0.6-1.0V, and the reaction time is 10-20 min.
4. 4. The method for preparing the CoO/CoP-LIG heterojunction water electrolysis catalyst according to claim 1, wherein in the third step, LIG size of Co (OH) 2 nano-sheets grown on the surface is 1-2 cm 2 , sodium hypophosphite consumption is 0.1-0.2 g, reaction temperature in a tube furnace is 300-350 ℃, and heat preservation time is 1.5-2.5 h.

Description

Preparation method of CoO/CoP-LIG heterojunction water electrolysis catalyst Technical Field The invention relates to a preparation method and application of a CoO/CoP-LIG heterojunction electrolyzed water catalyst, and belongs to the technical field of electrolyzed water material preparation methods. Background Electrolytic water hydrogen production is considered as one of the most potential green technologies, and the core of the technology is to efficiently and cleanly decompose water molecules into hydrogen and oxygen by utilizing electric energy generated by renewable energy sources. The process involves mainly two half reactions, a cathodic Hydrogen Evolution Reaction (HER) and an anodic Oxygen Evolution Reaction (OER). However, these two reactions, especially OER, involve complex multiple electron transfer processes and high reaction energy barriers, resulting in slow kinetics, requiring the application of overpotential well above the theoretical value (1.23V), resulting in significant electrical energy loss. Commercial electrolytic cells have long relied heavily on HER catalysts represented by platinum (Pt) based materials and OER catalysts represented by iridium (Ir), ruthenium (Ru) oxides. Although these noble metal catalysts are excellent in performance, their extremely low natural abundance and high cost directly restrict the large-scale popularization and industrialization development of the water electrolysis hydrogen production technology. In order to get rid of the dependence on noble metals, the scientific research world directs the eyes to transition metal-based materials with rich reserves and low cost. Among them, transition metal oxides, phosphides, sulfides, etc., have been rapidly developed in the past decade due to their unique electronic structures and tunable catalytic activities. These materials are capable of efficiently adsorbing and activating reaction intermediates by exposing unsaturated coordination sites or forming specific crystal planes. However, they generally face two major bottlenecks, namely poor intrinsic conductivity, which is unfavorable for rapid electron transport, and the adsorption energy to reaction intermediates (such as H in HER and OOH in OER) often deviates from the optimal value, so that the difference between the intrinsic activity and the noble metal still exists. Therefore, through exquisite material design and structural engineering, the conductivity, the number of active sites and the inherent activity of the non-noble metal catalyst are synchronously improved, and the method is a key point for pushing the water electrolysis technology to practical application. Aiming at the inherent defect of a single-component catalyst, the construction of a heterojunction interface has become a revolutionary strategy for breaking through performance bottlenecks. Heterojunction catalysts refer to composite structures formed by the close coupling of two or more different chemical components or crystalline phases on the nanometer scale. The core advantages are derived from a synergistic effect and electronic regulation induced at the interface. First, the formation of a heterojunction interface drives charge redistribution across the interface, thereby optimizing the local electron density of the active sites, making their adsorption energy to the reaction intermediates more similar to the "volcanic pattern" peak, while reducing the energy barrier of the reaction step. Second, the synergy between the different components of the heterojunction may expose more active interfaces and defect sites. More importantly, in long-term operation, the heterojunction structure can effectively relieve the problems of dissolution, oxidation or agglomeration of a single component under severe potential, so that the durability of the catalyst is remarkably improved. Meanwhile, the heterojunction nano material is anchored on the high-efficiency conductive substrate, and a three-dimensional integrated electrode is constructed, so that the heterojunction nano material is a necessary path for further improving the overall performance. The technology of laser processing graphene stands out, and the method becomes a very promising substrate preparation method. The method utilizes a laser processing technology to instantly convert a precursor material into three-dimensional porous graphene. The graphene substrate not only has excellent conductivity and huge specific surface area, and provides an ideal platform for the loading of active substances and the construction of electron/mass transfer channels, but also has abundant functional groups and defect sites on the surface, which can generate strong chemical coupling with heterojunction nano particles, so that the interface is further stabilized and the charge transfer is promoted. The strong combination of the active heterojunction and the functionalized carbon skeleton represents an important development direction of the next-generation hi