CN104724758A - Method for preparing WO3 nano-layer material - Google Patents

Abstract

The invention discloses a method for preparing a multi-nano-layer WO3 array material and belongs to the technical field of nano-material preparation. The preparation method comprises the following steps: by directly taking conductive glass as a substrate, adopting sodium tungstate as a tungsten source, controlling the solution under a certain pH value and synthesizing the WO3 nano-layer material through a one-step hydrothermal method. The method provided by the invention is simple and safe, low in preparation cost and easy to control; and the prepared nano-array is uniform in shape, directly grows on an FTO substrate and can form a good conductive channel with a conductive substance, has a wide application prospect in the solar cell field and the photocatalysis field, and simultaneously is an ideal material for preparing an electrochromic film, a photochromic film and a gas sensitive sensor.

Description

A kind of WO 3the preparation method of nanoscale twins material

Technical field:

The invention belongs to technical field of nanometer material preparation, particularly a kind of WO of one ₃the preparation method of nanoscale twins material.This material at photocatalytic degradation, photolysis water hydrogen, prepare in electrode of solar battery, electrochomeric films, photochromic film, gas sensor etc. and be with a wide range of applications.

Background technology:

WO ₃be a kind of important semiconductor material, in photochromic, electrochromism, photocatalytic degradation, gas sensor, solar cell etc., there is widespread use, receive much concern as typical n-type semiconductor always.The performance of these aspects depends on WO to a great extent ₃the nanostructure of the size of nano structured unit, pattern and assembling thereof, just because of the decisive role of structure in its performance of material.

WO ₃nano-array preparation method has a lot, and that reports in document has thermal evaporation, collosol and gel preparation method, chemical process etc.Thermal evaporation needs the high temperature of 900 ~ 1000 DEG C, and growth technique condition is harsh, and equipment requirements is high, repeatable poor; Collosol and gel preparation method preparation process is simple, but the report directly grown on base material is less, and is difficult to obtain the orderly nanostructure of array; The nanostructure sticking power that chemical process grows at substrate surface is more weak, thus limits its application; And the one step hydro thermal method that present method uses is comparatively simple, equipment requirements is low, products pure, and favorable repeatability is also applicable to scale operation, can directly at the WO that conductive glass base aerial is orderly ₃nanoscale twins array.

WO ₃nanoscale twins array material and common WO ₃material is compared has larger advantage.First, WO ₃nanoscale twins array has larger specific surface area, for providing more electrical contact between particle, add electron transfer rate, improve catalytic activity.Secondly, WO ₃nanoscale twins array dense regular, avoids common WO ₃the defect that material internal is more, reduces compound.In addition, the WO for preparing of present method ₃nanoscale twins array directly grows out on FTO, better with the contact of conductive substrates, and electron injection and transfer rate are faster, thus improve the performance of material.Therefore, many nanoscale twins WO ₃array material has very wide application prospect.

Summary of the invention:

The invention reside in and a kind of many nanoscale twins WO is provided ₃the preparation method of array material.

A kind of many nanoscale twins WO ₃the preparation method of array material is the simple hydrothermal method of employing one step, using FTO as growth substrates, with Na ₂wO ₄2H ₂o is raw material, oxalic acid and (NH ₄) ₂sO ₄for stablizer, then drip HNO ₃regulation and control precursor aqueous solution pH value is 1 ~ 1.5.The concrete steps of the method are as follows:

(1) clean Conducting Glass, remove Conducting Glass surface contamination layer, obtain the Conducting Glass cleaned, ozonize 15 ~ 30 minutes under UV ultraviolet lamp, form water-wetted surface, be then placed in loft drier and carry out 60 DEG C of drying treatment;

(2) according to deionized water and 16mol/LHNO ₃the volume ratio of solution is that 1:1 prepares HNO ₃reaction solution a;

(3) by Na ₂wO ₄2H ₂o powder adds in deionized water, is configured to the sodium tungstate solution that substance withdrawl syndrome is 0.023 ~ 0.024mol/L;

(4) in step (3) gained solution, HNO is dripped ₃reaction solution a is to regulate and control pH value to 1 ~ 1.5 of sodium tungstate solution;

(5) will with Na ₂wO ₄2H ₂o molar feed ratio example is the oxalic acid of 1:10 ~ 1:40 and the (NH of 1:3 ~ 1:6 ₄) ₂sO ₄add in step (4) in gained solution respectively, fully stir and obtain end reaction precursor aqueous solution;

(6) Conducting Glass in step (1) being positioned over liner is in the autoclave of tetrafluoroethylene, and implantation step (5) gained precursor aqueous solution, adopt hydrothermal synthesis reaction method, keep 180 DEG C to react 8 hours, then naturally cool to room temperature;

(7) conductive glass takes out after terminating by reaction, repeatedly cleans to neutrality respectively, then in loft drier, carry out 60 DEG C of drying treatment, namely obtain many nanoscale twins WO with deionized water and dehydrated alcohol ₃array material.

Whole reaction process chemical equation can be expressed as follows:

Na ₂WO ₄+2H ⁺→H ₂WO ₄+2Na ⁺

H ₂WO ₄→WO ₃+H ₂O

Tool of the present invention has the following advantages:

Method manufacture craft of the present invention is simple, the WO prepared ₃nano-array pattern is even, consistent size, and is directly grown on FTO substrate, forms better conductive channel, be more conducive to the transmission of electronics with conductive substrates.

Accompanying drawing illustrates:

Fig. 1 is many nanoscale twins WO ₃the scanning electron microscope (SEM) photograph of array material

Embodiment:

(1) FTO substrate is cleaned: utilize acetone ultrasonic cleaning 10min, then use dehydrated alcohol and each 20min of deionized water ultrasonic cleaning.Remove FTO surface contamination layer, obtain the FTO substrate cleaned, ozonize 15 minutes under UV ultraviolet lamp, then puts into loft drier and carries out 60 DEG C of drying treatment.Ultrapure water resistivity used need at 16 more than Ω cm;

(2) HNO of deionized water and 16mol/L is measured respectively ₃the each 20ml of solution puts into 50ml beaker, obtains clarifying reaction liquid a after magnetic agitation 10min is dispersed;

(3) measure 30ml deionized water and put into 100ml beaker, and take the NaWO of 0.231g with electronic balance ₃2H ₂o joins in deionized water, and magnetic agitation 10min is to fully dissolving;

(4) pH of solution in pH meter monitoring step (3) is used, and slow dropwise reaction liquid a, until pH value of solution is in 1 ~ 1.5 scope, now solution produces yellow mercury oxide;

(5) join in above-mentioned solution with the oxalic acid that electronic balance takes 1.26g, magnetic agitation 5min, the then (NH taking 0.32g with electronic balance ₄) ₂sO ₄join in solution, magnetic agitation 10min is to resolution of precipitate;

(6) deionized water is joined the solution after resolution of precipitate, and solution is settled to 70ml, full and uniform stirring obtains reaction precursor solution;

(7) conductive glass in step (1) is uprightly fixedly put into the 50ml autoclave that liner is tetrafluoroethylene, get precursor aqueous solution 40ml in step (6) and slowly inject autoclave, 180 DEG C are reacted 8 hours, then naturally cool to room temperature;

(8) FTO is taken out, residue deionized water on the reacted FTO of being deposited in and dehydrated alcohol are rinsed well, on FTO glass, the flaxen oxidation tungsten film of visible one deck, then carries out drying treatment 6 hours in 60 DEG C of loft drier, i.e. obtained many nanoscale twins WO on FTO ₃array material.The oxalic acid added and wolframic acid define complex compound, thus inhibit the generation of precipitation, and the sodium sulfate added facilitates WO ₃grow to array direction.Obtained WO ₃nano-chip arrays material as shown in Figure 1.

Claims (1)

1. a WO ₃the preparation method of nanoscale twins material, is the simple hydrothermal method of employing one step, it is characterized in that, comprise step as follows:

(1) clean Conducting Glass, remove Conducting Glass surface contamination layer, obtain the Conducting Glass cleaned, ozonize 15 ~ 30 minutes under UV ultraviolet lamp, be then placed in loft drier and carry out 60 DEG C of drying treatment;

(2) according to deionized water and 16M HNO ₃the volume ratio of solution is that 1:1 prepares HNO ₃reaction solution a;

(3) by Na ₂wO ₄2H ₂o powder adds in deionized water, is configured to the sodium tungstate solution that substance withdrawl syndrome is 0.023 ~ 0.024mol/L;

(4) in step (3) gained solution, HNO is dripped ₃reaction solution a is to regulate and control pH value to 1 ~ 1.5 of sodium tungstate solution;

(5) will with Na ₂wO ₄2H ₂o molar feed ratio example is the oxalic acid of 1:10 ~ 1:40 and the (NH of 1:3 ~ 1:6 ₄) ₂sO ₄add in step (4) in gained solution respectively, fully stir and obtain end reaction precursor aqueous solution;

(6) Conducting Glass in step (1) being positioned over liner is in the autoclave of tetrafluoroethylene, and implantation step (5) gained precursor aqueous solution, adopt hydrothermal synthesis reaction method, keep 180 DEG C to react 8 hours, then naturally cool to room temperature;

(7) conductive glass takes out after terminating by reaction, repeatedly cleans to neutrality respectively, then in loft drier, carry out 60 DEG C of drying treatment, namely obtain many nanoscale twins WO with deionized water and dehydrated alcohol ₃array material.