Synthesis of Ag9(SiO4)2NO3 through a reactive flux method and its visible-light photocatalytic performances

Abstract

Ag9(SiO4)2NO3 was prepared by a reactive flux method. The structures, morphologies, and light absorption properties were investigated. Owing to the polar crystal structure, an internal electric field can be formed inside the material, which can facilitate the photogenerated charge separation during the photocatalytic process. Based on both the wide light absorption spectra and high charge separation efficiency originated from the polarized internal electric field, Ag9(SiO4)2NO3 exhibit higher efficiency over Ag3PO4 during the degradation of organic dyes under visible light irradiation, which is expected to be a potential material for solar energy harvest and conversion.

Efficient Photocatalytic Hydrogen Generation from Water over CdS Nanoparticles Confined Within an Alumina Matrix

“…The longert he lifetime is, the more possiblet hat photogenerated electrons and holes participate in photocatalytic re-actions. [40,41] As shown in Figure 8, the excited state of CdS LDH displays am uch longerl ifetimet han that of CdS CdðOHÞ 2 .T he average lifetimew as determined using at wo-exponential decay function: t av ¼ t 1 a 1 þ t 2 a 2 (t 1 , t 2 are the lifetime, a 1 , a 2 are normalized pre-exponential factors). The average lifetime of CdS LDH is t = 114.40 ns, much longer than that of CdS CdðOHÞ 2 (t = 62.37 ns).…”

Synthesis of novel visible light response Ag 10 Si 4 O 13 photocatalyst

“…Calculations method about the CB and VB was according to our previous work. [24,25] And the estimated CB and In order to evaluate photocatalytic activities of as-prepared samples. Photodegradation of organic dye solutions and photocatalytic O2 production experiments were carried out.…”

Enhancing Charge Separation in Photocatalysts with Internal Polar Electric Fields

“…[60] Based on above research, an internal polar electric fieldw as found in the crystal structure of Ag 9 (SiO 4 ) 2 NO 3 ,i nw hich the separated single SiO 4 tetrahedra and NO 3 polyhedra are coordinated with Ag cations. [61] Due to d 10 -d 10 interactions of the short AgÀAg bonds, Ag 9 (SiO 4 ) 2 NO 3 exhibited stronga bsorption in the visible-light region. Calculationsc onfirmed that the CB and VB of Ag 9 (SiO 4 ) 2 NO 3 are mainly composed of Oa nd Ag atoms, respectively.U pon light irradiation of Ag 9 (SiO 4 ) 2 NO 3 , electrons weree xcited andt ransfer from the VB to the CB, which can be described as electron transfer from Oatoms to coordinated Ag atoms in the material.…”

“…Calculationsc onfirmed that the CB and VB of Ag 9 (SiO 4 ) 2 NO 3 are mainly composed of Oa nd Ag atoms, respectively.U pon light irradiation of Ag 9 (SiO 4 ) 2 NO 3 , electrons weree xcited andt ransfer from the VB to the CB, which can be described as electron transfer from Oatoms to coordinated Ag atoms in the material. [61] The existence of NO 3 À groups in the crystal structure of Ag 9 (SiO 4 ) 2 NO 3 can generate internal electric fields, and its directioni sin accord with the directions of electron and hole migration (Figure 8a). Therefore, an additional driving force facilitates the charge separation and result in enhanced photocatalytic activities of Ag 9 (SiO 4 ) 2 NO 3 in oxygen evolution (Figure 8c).…”

“…Therefore, an additional driving force facilitates the charge separation and result in enhanced photocatalytic activities of Ag 9 (SiO 4 ) 2 NO 3 in oxygen evolution (Figure 8c). [61] The SiO 4 distorted tetrahedral could change the bond energy of the AgÀO bond for tuning the light absorption and photocatalytic activities. The longest distorted SiO 4 chains in the Ag x Si y O z family were found in the crystal structure of Ag 10 Si 4 O 13 (Figure 8b).…”