Method for preparing graphene modified composite planar pH sensor

Abstract

Provided is a fabrication method for a composite planar pH sensor modified by graphene film including: slotting into substrate, setting copper foil on both sides, and setting leads on the copper foil; coating graphene film on the copper foils using micro mechanical stripping method to form the first graphene film and the second graphene film; depositing Sb layer and Sb.sub.2O.sub.3 layer successively on the first graphene film by magnetron sputtering method, and coating Nafion™ perfluorinated sulfonic acid membrane on the Sb.sub.2O.sub.3 layer by spin-coating method to fabricate pH working electrode; depositing Ag layer on the second graphene film and dipping in FeCl.sub.3 solution to form AgCl layer; coating the third graphene film on the AgCl layer to fabricate reference electrode. The composite planar pH sensor modified by graphene film may be used in pH measurement for solid, semisolid, mash and solution samples.

Claims

1. A fabrication method of a composite planar pH sensor modified by graphene film including the steps of: preparing a substrate including forming a slot on each of two sides of the substrate, setting a first copper foil and a second copper foil on a bottom of the slots respectively; and preparing leads on the first copper foil and the second copper foil by a printing process respectively in the substrate; preparing a pH working electrode including coating with a first graphene film on the first copper foil using a micro mechanical stripping method; depositing a Sb layer on the first graphene film by a magnetron sputtering method; depositing a Sb.sub.2O.sub.3 layer on a surface of the Sb layer by a magnetron sputtering method; coating with a membrane layer on a surface of the Sb.sub.2O.sub.3 layer by a spin-coating method; wherein the pH working electrode comprises: the first graphene film, the Sb layer, the Sb.sub.2O.sub.3 layer, and the membrane layer, wherein the first graphene film and the first copper foil are electrically connected to each other, preparing a reference electrode including coating with a second graphene film on a second copper foil using a micro mechanical stripping method; depositing a Ag layer on the second graphene film by a magnetron sputtering method; dipping in a FeCl.sub.3 solution to form a AgCl layer; coating with a third graphene film on the AgCl layer using a micro mechanical stripping method; wherein the second graphene film, the Ag layer, the AgCl layer, and the third graphene film together comprise the reference electrode.

2. The fabrication method of a composite planar pH sensor modified by graphene film according to claim 1, wherein, the depositing of the Sb layer is as follows: the magnetron sputtering method of depositing the Sb layer is RF magnetron sputtering, a target material is antimony, and a gas used is argon; the magnetron sputtering method of depositing the Sb layer is completed at room temperature, an RF magnetron sputtering time is 40˜50 min, an argon flow is 39 sccm, a vacuum is 3×10.sup.−4 Pa, a power is 65 W, and a process pressure is 1 Pa.

3. The fabrication method of a composite planar pH sensor modified by graphene film according to claim 1, wherein, the depositing of the Sb.sub.2O.sub.3 layer is as follows: a target material is antimony, and a gas is argon, and oxygen gas is added, the concentration ratio of argon and oxygen is 8:2, and a deposition time is 50 min.

4. The fabrication method of a composite planar pH sensor modified by graphene film according to claim 1, wherein, the depositing of the Ag layer is as follows: the magnetron sputtering method of depositing the Ag layer is RF magnetron sputtering, a target material is silver, and a gas is argon; the RF magnetron sputtering is completed at room temperature, a time is 20˜30 min, an argon flow is 30 sccm, a vacuum is 3×10.sup.−4 Pa, a power is 18 W, and a process pressure is 1 Pa.

5. The fabrication method of a composite planar pH sensor modified by graphene film according to claim 1, wherein, a concentration of a used ferric chloride solution is 0.1 mol/L, and a soak time is 30 s.

6. The fabrication method of a composite planar pH sensor modified by graphene film according to claim 1, wherein, a thickness of the Sb layer is 230˜250 nm, the Sb.sub.2O.sub.3 layer 40˜60 nm, and the membrane layer 1.5˜1.9 μm.

7. The fabrication method of a composite planar pH sensor modified by graphene film according to claim 1, wherein, a thickness of the Ag layer is 140˜160 nm, the AgCl layer 15˜25 nm, and the Ag layer is not covered with AgCl layer completely.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic of the composite planar pH sensor modified by graphene film.

(2) FIG. 2 is a schematic of the working electrode.

(3) FIG. 3 is a schematic of the reference electrode.

(4) In these figures, 1 is the working electrode, 2 is the first copper foil, 3 is the leads, 4 is the substrate, 5 is the second copper foil, 6 is the reference electrode, 11 is the Nafion™ perfluorinated sulfonic acid membrane, 12 is the Sb2O3 layer, 13 is the Sb layer, 14 is the first graphene film, 61 is the second graphene film, 62 is the Ag layer, 63 is the AgCl layer, 64 is the third graphene film.

DETAILED DESCRIPTION

(5) Further description of this invention is presented combined with the drawings, but this invention is not limited to this disclosed description.

(6) Said composite planar pH sensor modified by graphene film consists of working electrode 1, reference electrode 6 and substrate 4, as shown in FIG. 1.

(7) As shown in FIG. 2, said working electrode 1 and the first copper foil 2 are electrical connected each other with the help of the first graphene film 14.

(8) Sb layer 13 and Sb2O3 layer 12 are deposited on the top of the first graphene film 14, and then Nafion™ perfluorinated sulfonic acid membrane is coating on the surface of the Sb2O3 layer 12.

(9) As shown in FIG. 3, said reference electrode 6 consists of the second graphene film 61, the Ag layer 62, the AgCl layer 63, and the third graphene film 64. The second graphene film 61 is deposited on the surface of the second copper foil 62; on the surface of the second graphene film 61, the Ag layer 62, the AgCl layer 63, and the third graphene film 64 are deposited in sequence.

(10) Said the fabrication method of a composite planar pH sensor modified by graphene film is described below:

(11) Preparation of the substrate 4: slotting on the two sides of the substrate 4, then setting the first copper foil 2 and the second copper foil 5 on the bottom of the slots respectively; preparation leads 3 on the first copper foil 2 and the second copper foil 5 by printing process respectively in the substrate 4; Preparation of the pH working electrode 1: coating with the first graphene film 14 on the first copper foil 2 using micro mechanical stripping method; depositing the Sb layer 13 on the first graphene film 14 by magnetron sputtering method; depositing the Sb2O3 layer 12 on the surface of the Sb layer 13 by magnetron sputtering method; coating with Nafion™ perfluorinated sulfonic acid membrane 11 on the surface of the Sb2O3 layer 12 by spin-coating method; the pH working electrode 1 is consist of the first graphene film 14, the Sb layer 13, the Sb2O3 layer 12, and the Nafion™ perfluorinated sulfonic acid membrane 11, in which the first graphene film 14 and the first copper foil 2 are electrical connected each other. The thickness of the Sb layer 13 is 240 nm, the Sb2O3 layer 12˜50 nm, the Nafion™ perfluorinated sulfonic acid membrane 1.7 μm.

(12) Preparation of the reference electrode 6: coating with the second graphene film 61 on the second copper foil 2 using micro mechanical stripping method; depositing the Ag layer 62 on the second graphene film 61 by magnetron sputtering method; dipping in FeCl3 solution to form AgCl layer 63, and the transformation is incomplete; coating with the third graphene film 64 on the AgCl layer 63 using micro mechanical stripping method; the second graphene film 61, the Ag layer 62, the AgCl layer 63, and the third graphene film 64 consist of the reference electrode 6. The thickness of the Ag layer 62 is ˜150 nm, the thickness of the AgCl layer 63 is ˜15 nm, and the Ag layer 62 is not covered with AgCl layer 63 completely.

Preferred Embodiment 1

(13) The following describes a preferred embodiment of this method and device with composite planar pH sensor modified by graphene film as an example.

(14) Step 1. Preparation of the substrate 4: slotting on the two sides of the substrate 4, then setting the first copper foil 2 and the second copper foil 5 on the bottom of the slots respectively; preparation leads 3 on the first copper foil 2 and the second copper foil 5 by printing process respectively in the substrate 4.

(15) Step 2. Preparation of the pH working electrode 1: coating with the first graphene film 14 on the first copper foil 2 using micro mechanical stripping method; depositing the Sb layer 13 on the first graphene film 14 by magnetron sputtering method, the target material is antimony, and the gas is argon; the sputtering is completed at room temperature, the time is 40-50 min, the flow is 39 sccm, the vacuum is 3×10.sup.4 Pa, the power is 65 W, and the process pressure is 1 Pa, the thickness of the Sb layer 13 is 240 nm; depositing the Sb2O3 layer 12 on the surface of the Sb layer 13 by magnetron sputtering method, the target material is antimony, and the gas is argon, also the oxygen gas is added, the concentration ratio of argon and oxygen is 8:2, and the deposition time is 50 min, the thickness of Sb2O3 layer 12 is −50 nm; coating with Nafion™ perfluorinated sulfonic acid membrane 11 on the surface of the Sb2O3 layer 12 by spin-coating method, the thickness of the Nafion™ perfluorinated sulfonic acid membrane is 1.7 μm.

(16) Step 3. Preparation of the reference electrode 6: coating with the second graphene film 61 on the second copper foil 2 using micro mechanical stripping method; depositing the Ag layer 62 on the second graphene film 61 by magnetron sputtering method, the target material is silver, and the gas is argon; the sputtering is completed at room temperature, the time is 20˜30 min, the flow is 30 sccm, the vacuum is 3×10.sup.−4 Pa, the power is 18 W, and the process pressure is 1 Pa, the thickness of the Ag layer 62 is 150 nm; dipping in FeCl3 solution to form AgCl layer 63, and the transformation is incomplete, the concentration of the used ferric chloride solution is 0.1 mol/L, and the soak time is 30 s, and the thickness of the AgCl layer 63 is 15 nm; coating with the third graphene film 64 on the AgCl layer 63 using micro mechanical stripping method.

(17) This preferred embodiment is the optimal implementation scheme, but this invention is not limited to this disclosed implementation scheme. The protection scope of this invention includes any obvious improvements, replaces or variations by technical staff of this area.