By analysing the energy level structure of nano-TiO2 and the performance of degrading formaldehyde,the photocatalytic mechanism of nano-TiO2 was discussed.It was found that the size of the particles is a key facto...By analysing the energy level structure of nano-TiO2 and the performance of degrading formaldehyde,the photocatalytic mechanism of nano-TiO2 was discussed.It was found that the size of the particles is a key factor which determines the photocatalytic efficiency in the competing process between spearation and recombination of the charge-carriers.When particles dispersed at nanometer scale,the quantum size effect and the surface effciency of separation is strong,charge-carriers can quickly transfer to the surface.Them they react with the oxygen and water absorbed on the surface of materials.Thus two kinds of groups hydroxyl radicals and anion peroxide radicals,will form.Having good oxidize power,these groups can seize electron or hydrogen atoms from the polluted substances on the material surface.Subsequently,the chain reactions are induced.As a result,contaminations are mineralized and degraded.展开更多
The electro-oxidation of formaldehyde on a gold electrode in a gold electrode in a solution containing0.1mol ·L -1 Na2 CO3＋0. 1mol·L - 1NaHCO3＋0. 1 mol·L, - 1 HCHO was investigated bycyclic voltammetr...The electro-oxidation of formaldehyde on a gold electrode in a gold electrode in a solution containing0.1mol ·L -1 Na2 CO3＋0. 1mol·L - 1NaHCO3＋0. 1 mol·L, - 1 HCHO was investigated bycyclic voltammetry and in -situ FTIR spetroscopy . The experimental results demonstrated that the oxidation of formaldehyde at different potential range connected with different surface species of gold. At lower potentials, the main product of formaldehyde oxidationwas HCOO-, and at higher potentials, the products HCOO- and CO2 were detected simultaneously. From the results, a possible reaction mechanism was proposed.展开更多
文摘By analysing the energy level structure of nano-TiO2 and the performance of degrading formaldehyde,the photocatalytic mechanism of nano-TiO2 was discussed.It was found that the size of the particles is a key factor which determines the photocatalytic efficiency in the competing process between spearation and recombination of the charge-carriers.When particles dispersed at nanometer scale,the quantum size effect and the surface effciency of separation is strong,charge-carriers can quickly transfer to the surface.Them they react with the oxygen and water absorbed on the surface of materials.Thus two kinds of groups hydroxyl radicals and anion peroxide radicals,will form.Having good oxidize power,these groups can seize electron or hydrogen atoms from the polluted substances on the material surface.Subsequently,the chain reactions are induced.As a result,contaminations are mineralized and degraded.
文摘The electro-oxidation of formaldehyde on a gold electrode in a gold electrode in a solution containing0.1mol ·L -1 Na2 CO3＋0. 1mol·L - 1NaHCO3＋0. 1 mol·L, - 1 HCHO was investigated bycyclic voltammetry and in -situ FTIR spetroscopy . The experimental results demonstrated that the oxidation of formaldehyde at different potential range connected with different surface species of gold. At lower potentials, the main product of formaldehyde oxidationwas HCOO-, and at higher potentials, the products HCOO- and CO2 were detected simultaneously. From the results, a possible reaction mechanism was proposed.
