CN101244382A - Process for producing N doping TiO2 - Google Patents

Abstract

The invention discloses a preparation method of N-doped TiO2 photocatalyst, comprising a plurality of steps as followings: firstly, weighing 0.2 to 2 milliliter HCl solution with a concentration of 37.5%, quickly adding the HCl solution into a mixed solution of tetrabutyl titanate and isopropanol while strenuously agitating the HCl solution, then strenuously agitating for 10 to 20 minutes at a constant temperature of 25 DEG C, then slowly dropping a deionized water solution dissolved with 10% to 60% urea to obtain a yellow transparent sol, standing for 5 to 30 minutes to form a milkiness translucent gel; secondly, hermetically aging the prepared gel for 5 days, drying the wet aged gel for 5 hours at a vacuum condition and a temprature of 65 DEG C to obtain loose tawny dry xerogel powder, then putting the powder into a muffle furnace and calcining for 2 hours to obtain the N-doped TiO2 photocatalyst. The invention is characterized in that urea is used as a nitrogen source to prepare nitrogen-doped TiO2 photocatalyst with an acid catalysis sol-gel method. The N-doped TiO2 photocatalyst prepared by the method has the advantages of good photocatalysis activity when excited by a visible light.

Description

A kind of N doped Ti O 2The preparation method of photochemical catalyst

Technical field

The present invention relates to a kind of N doped Ti O ₂The preparation method of photochemical catalyst.

Background technology

Nano-TiO ₂Has good performance as photochemical catalyst.In recent years, use nano-TiO ₂Become a focus of environmental science Deng the research of the pollutant in the conductor photocatalysis degraded water body, be considered to one of the most promising, the most effective processing means.But TiO ₂Its limitation is arranged self: greater band gap (E _g=3.0～3.2eV), its light absorption only is confined to the ultraviolet light zone, and the content of sunshine middle-ultraviolet lamp is less than 5%, so make solar energy utilization rate very low.Studies show that nonmetal doping is expansion TiO ₂The effective means of the spectral response range of photochemical catalyst and its catalytic efficiency of raising, N doping vario-property TiO ₂, be present nonmetal doping modification TiO ₂In study at most a kind of element.At present, to TiO ₂The method of carrying out the N doping has: (1) N ₂Or NH ₃High-temperature calcination TiO under the atmosphere ₂, (2) Ti (OH) ₄Or TiO ₂After urea fully mixes, calcining at high temperature, (3) TiO ₂Nano material impregnated in calcining at high temperature in the ammoniacal liquor, (4) TiN annealing in process.

Summary of the invention

The present invention is nitrogenous source with urea, adopts the acid catalysis sol-gel process to prepare nitrating TiO ₂Photochemical catalyst.

This preparation method has the following steps:

1) taking by weighing 0.2～2ml concentration is that 37.5% HCl adds it in mixed solution of butyl titanate and isopropyl alcohol under vigorous stirring fast, at 25 ℃ of following constant temperature vigorous stirring 10～20min, to be dissolved with urea, concentration again and be 10～60% deionized water solution slowly splashes in the above-mentioned solution, form yellow transparent colloidal sol, after leaving standstill 5～30min, just form the milky translucent gels;

2) with the airtight ageing of the wet gel that makes 5 days, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on then in the Muffle furnace, and roasting 2h promptly gets N doped Ti O ₂Photochemical catalyst.

Above-mentioned steps 1) mol ratio of each component is a butyl titanate in: isopropyl alcohol: deionized water=1: 20: 4.

The invention has the beneficial effects as follows the nitrating TiO that makes ₂Photochemical catalyst has the good light catalytic activity under excited by visible light.

The specific embodiment

Implementation column 1

Pipette 0.25ml concentration and be in the butyl titanate and aqueous isopropanol that 37.5% HCl mixes its quick adding under vigorous stirring by a certain percentage, at 25 ℃ of following constant temperature vigorous stirring 10min, deionized water solution is slowly splashed in the above-mentioned solution, the mol ratio of controlling each component is a butyl titanate: isopropyl alcohol: deionized water=1: 20: 4 again.After leaving standstill 5min, just form the milky translucent gels.With the airtight ageing 5d of the wet gel that makes, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on roasting 2h in the Muffle furnace then, promptly gets N doped Ti O ₂Sample.When not containing urea in the deionized water, promptly pure TiO ₂Photocatalytic activity under tungsten lamp is 1.

Implementation column 2

Pipette 0.3ml concentration and be in the butyl titanate and aqueous isopropanol that 37.5% HCl mixes its quick adding under vigorous stirring by a certain percentage, at 25 ℃ of following constant temperature vigorous stirring 12min, to be dissolved with urea, concentration again and be 20% deionized water solution and slowly splash in the above-mentioned solution, the mol ratio of controlling each component is a butyl titanate: isopropyl alcohol: deionized water=1: 20: 4.After leaving standstill 6min, just form the milky translucent gels.With the airtight ageing 5d of the wet gel that makes, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on roasting 2h in the Muffle furnace then, promptly gets N doped Ti O ₂Sample.When urea quality concentration is 20% in the deionized water, N doped Ti O ₂Photocatalytic activity under tungsten lamp is 1.29.

Implementation column 3

Pipette 0.8ml concentration and be in the butyl titanate and aqueous isopropanol that 37.5% HCl mixes its quick adding under vigorous stirring by a certain percentage, at 25 ℃ of following constant temperature vigorous stirring 15min, to be dissolved with urea, concentration again and be 35% deionized water solution and slowly splash in the above-mentioned solution, the mol ratio of controlling each component is a butyl titanate: isopropyl alcohol: deionized water=1: 20: 4.After leaving standstill 20min, just form the milky translucent gels.With the airtight ageing 5d of the wet gel that makes, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on roasting 2h in the Muffle furnace then, promptly gets N doped Ti O ₂Sample.When urea quality concentration is 35% in the deionized water, N doped Ti O ₂Photocatalytic activity under tungsten lamp is 1.46.

Implementation column 4

Pipette 1.3ml concentration and be in the butyl titanate and aqueous isopropanol that 37.5% HCl mixes its quick adding under vigorous stirring by a certain percentage, at 25 ℃ of following constant temperature vigorous stirring 18min, to be dissolved with urea, concentration again and be 42% deionized water solution and slowly splash in the above-mentioned solution, the mol ratio of controlling each component is a butyl titanate: isopropyl alcohol: deionized water=1: 20: 4.After leaving standstill 25min, just form the milky translucent gels.With the airtight ageing 5d of the wet gel that makes, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on roasting 2h in the Muffle furnace then, promptly gets N doped Ti O ₂Sample.When urea quality concentration is 42% in the deionized water, N doped Ti O ₂Photocatalytic activity under tungsten lamp is 1.22.

Implementation column 5

Pipette 1.8ml concentration and be in the butyl titanate and aqueous isopropanol that 37.5% HCl mixes its quick adding under vigorous stirring by a certain percentage, at 25 ℃ of following constant temperature vigorous stirring 20min, to be dissolved with urea, concentration again and be 55% deionized water solution and slowly splash in the above-mentioned solution, the mol ratio of controlling each component is a butyl titanate: isopropyl alcohol: deionized water=1: 20: 4.After leaving standstill 30min, just form the milky translucent gels.With the airtight ageing 5d of the wet gel that makes, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on roasting 2h in the Muffle furnace then, promptly gets N doped Ti O ₂Sample.When urea quality concentration is 55% in the deionized water, N doped Ti O ₂Photocatalytic activity under tungsten lamp is 1.15.

Claims (2)

1. N doped Ti O ₂The preparation method of photochemical catalyst is characterized in that: this preparation method is nitrogenous source with urea, adopts the acid catalysis sol-gel process to prepare nitrating TiO ₂Photochemical catalyst, this preparation method has the following steps:

1) taking by weighing 0.2～2ml concentration is that 37.5% HCl adds it in mixed solution of butyl titanate and isopropyl alcohol under vigorous stirring fast, at 25 ℃ of following constant temperature vigorous stirring 10～20min, to be dissolved with urea, concentration again and be 10～60% deionized water solution slowly splashes in the above-mentioned solution, form yellow transparent colloidal sol, after leaving standstill 5～30min, just form the milky translucent gels;

2) with the airtight ageing of the wet gel that makes 5 days, the wet gel good through ageing obtains loose yellowish-brown dry gel powder behind 65 ℃ of following vacuum drying 5h, be placed on then in the Muffle furnace, and roasting 2h promptly gets N doped Ti O ₂Photochemical catalyst.

2. preparation method according to claim 1 is characterized in that: the mol ratio of each component is a butyl titanate above-mentioned steps 1): isopropyl alcohol: deionized water=1: 20: 4.