Summary of the invention
The purpose of this invention is to provide a kind of technique simple, prepared material highly sensitive, response-time of recovery is short has lower concentration H
2the preparation method of S sensitivity characteristics iron molybdate micro Nano material.
The object of the present invention is achieved like this:
(1) by ammonium molybdate powder 4 hours preparation MoO of 500 ℃ of temperature lower calcinations in air
3powder; MoO by 30-35mg
3powder, 0.5-0.6g urea and 30-35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, and at 200 ℃ of temperature, heating is 24 hours, and cooling rear cleaning, drying, obtain flowers shape MoS
2powder raw material;
(2) by MoS
2powder, in air, is calcined 2-5 hour under 400 ℃ of-600 ℃ of conditions;
(3) the 0.01-0.075g products therefrom is dissolved in to the Fe (NO of 0.01-0.02mol/L
3)
3in solution, 50-60 ℃ of stirring in water bath 1-3 hour, suction filtration;
(4) upper step product is joined to the Fe (NO of 0.01-0.02mol/L
3)
350-60 ℃ of stirring in water bath 1-3 hour in solution;
(5) by products therefrom vacuum-drying;
(6) products therefrom is with the temperature rise rate 400-600 ℃ of calcining 3-5 hour in air of 5 ℃/min, and naturally cooling, obtain having lower concentration H
2s sensitivity characteristics iron molybdate micro Nano material.
Preparation method of the present invention is simple, and prepared iron molybdate micro Nano material is to lower concentration H
2s is highly sensitive, selectivity good, response-time of recovery is short, the H of 0.5ppm can be detected under 270 ℃
2s gas.
Embodiment
Below for example the present invention is described in more detail.
Embodiment 1:
(1) starting material preparation: ammonium molybdate powder is calcined in air to 500 ℃ of 4 hours preparation MoO
3powder; MoO by 35mg
3powder, 0.6g urea and 35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, be placed in autoclave, in baking oven 200 ℃, heat 24 hours, cooling rear cleaning, drying, obtain flowers shape MoS
2starting material.
(2) by 1g MoS
2powder in air 500 ℃ annealing 4 hours.
(3) the products therefrom 0.075g that will anneal is dissolved in the Fe (NO of the 0.014mol/L of 300mL
3)
3in solution, 50 ℃ of stirring in water bath 2 hours, suction filtration.
(4) the previous step product is all joined to the Fe (NO of the 0.014mol/L of 300mL
3)
3in solution, 50 ℃ of stirring in water bath are 2 hours.
(5) by products therefrom vacuum-drying in 40 ℃.
(6) products therefrom was with 500 ℃ of heating of the temperature rise rate of 5 ℃/min 4 hours.
Embodiment 2:
(1) starting material preparation: ammonium molybdate powder is calcined in air to 500 ℃ of 4 hours preparation MoO
3powder; MoO by 35mg
3powder, 0.6g urea and 35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, be placed in autoclave, in baking oven 200 ℃, heat 24 hours, cooling rear cleaning, drying, obtain flowers shape MoS
2starting material.
(2) by 1g MoS
2powder in air 500 ℃ annealing 4 hours.
(3) the products therefrom 0.01g that will anneal is dissolved in the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 50 ℃ of stirring in water bath 2 hours, suction filtration.
(4) the previous step product is all joined to the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 50 ℃ of stirring in water bath are 2 hours.
(5) by products therefrom vacuum-drying in 40 ℃.
(6) products therefrom was with 500 ℃ of heating of the temperature rise rate of 5 ℃/min 4 hours.
Embodiment 3:
(1) starting material preparation: ammonium molybdate powder is calcined in air to 500 ℃ of 4 hours preparation MoO
3powder; MoO by 35mg
3powder, 0.6g urea and 35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, be placed in autoclave, in baking oven 200 ℃, heat 24 hours, cooling rear cleaning, drying, obtain flowers shape MoS
2starting material.
(2) by 1g MoS
2powder in air 500 ℃ annealing 4 hours.
(3) the products therefrom 0.01g that will anneal is dissolved in the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 60 ℃ of stirring in water bath 2 hours, suction filtration.
(4) the previous step product is all joined to the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 60 ℃ of stirring in water bath are 2 hours.
(5) by products therefrom vacuum-drying in 40 ℃.
(6) products therefrom adds 3 hours with 500 ℃ of the temperature rise rates of 5 ℃/min.
Embodiment 4:
(1) starting material preparation: ammonium molybdate powder is calcined in air to 500 ℃ of 4 hours preparation MoO
3powder; MoO by 35mg
3powder, 0.6g urea and 35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, be placed in autoclave, in baking oven 200 ℃, heat 24 hours, cooling rear cleaning, drying, obtain flowers shape MoS
2starting material.
(2) by 1g MoS
2powder in air 500 ℃ annealing 4 hours.
(3) the products therefrom 0.01g that will anneal is dissolved in the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 50 ℃ of stirring in water bath 3 hours, suction filtration.
(4) the previous step product is all joined to the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 50 ℃ of stirring in water bath are 3 hours.
(5) by products therefrom vacuum-drying in 40 ℃.
(6) products therefrom adds 3 hours with 500 ℃ of the temperature rise rates of 5 ℃/min.
Embodiment 5:
(1) starting material preparation: ammonium molybdate powder is calcined in air to 500 ℃ of 4 hours preparation MoO
3powder; MoO by 35mg
3powder, 0.6g urea and 35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, be placed in autoclave, in baking oven 200 ℃, heat 24 hours, cooling rear cleaning, drying, obtain flowers shape MoS
2starting material.
(2) by 1g MoS
2powder in air 500 ℃ annealing 4 hours.
(3) the products therefrom 0.01g that will anneal is dissolved in the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 60 ℃ of stirring in water bath 3 hours, suction filtration.
(4) the previous step product is all joined to the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 60 ℃ of stirring in water bath are 3 hours.
(5) by products therefrom vacuum-drying in 40 ℃.
(6) products therefrom adds 3 hours with 600 ℃ of the temperature rise rates of 5 ℃/min.
Embodiment 6:
(1) starting material preparation: ammonium molybdate powder is calcined in air to 500 ℃ of 4 hours preparation MoO
3powder; MoO by 35mg
3powder, 0.6g urea and 35mg thioacetamide are dissolved in 15ml deionized water and 25ml alcohol mixed solution, be placed in autoclave, in baking oven 200 ℃, heat 24 hours, cooling rear cleaning, drying, obtain flowers shape MoS
2starting material.
(2) by 1g MoS
2powder in air 500 ℃ annealing 4 hours.
(3) the products therefrom 0.01g that will anneal is dissolved in the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 60 ℃ of stirring in water bath 3 hours, suction filtration.
(4) the previous step product is all joined to the Fe (NO of the 0.02mol/L of 300mL
3)
3in solution, 60 ℃ of stirring in water bath are 3 hours.
(5) by products therefrom vacuum-drying in 40 ℃.
(6) products therefrom adds 5 hours with 600 ℃ of the temperature rise rates of 5 ℃/min.
The gas sensitive device making method:
Gas sensor is made heater-type sintered type element by traditional method.Concrete making step is: sample thief a little, splash into appropriate ethanol, the furnishing pasty state, evenly be applied to the vitrified pipe outside with the Pt lead-in wire, after oven dry, vitrified pipe is welded on base and with RTD and connects.The device aging quick test of laggard promoting the circulation of qi in a day.
Air-sensitive test: under 270 ℃, carry out H
2the test of S gas sensitivity, add concentration to be respectively 0.5ppm, 1ppm, 5ppm, 10ppm, 30ppm, 50ppm.Under 270 ℃, carry out ethanol, acetone gas sensitivity test, add concentration to be respectively 100ppm, 200ppm, 300ppm, 500ppm.Referring to accompanying drawing 3, Fig. 4, Fig. 5 is respectively in the embodiment of the present invention 1 gained iron molybdate micro nano structure to gas with various (H
2s, ethanol, acetone) the test result of air-sensitive performance.Therefrom known, adopt the synthetic iron molybdate micro Nano material of the method, at identical temperature, to H
2s has good selectivity and higher sensitivity, and response-time of recovery is shorter simultaneously.