A green approach for the synthesis of novel Ag₃PO₄/SnO₂/porcine bone and its exploitation as a catalyst in the photodegradation of lignosulfonate into alkyl acids

Abstract

A novel Ag 3 PO 4 /SnO 2 /porcine bone composite photocatalyst was successfully prepared via an ion exchange method, which can convert lignin derivatives into small molecular acids upon exposure to visible light at room temperature at ambient pressure. The composition characterization, optical absorption properties and photocatalytic activities of the Ag 3 PO 4 /SnO 2 /porcine bone composites were thoroughly investigated. The certain role of each component of the composites in the degradation reaction was discussed: Ag 3 PO 4 acted as the major active component, while SnO 2 and porcine bone as cocatalyst contributed to improve the photocatalytic activity and stability of Ag 3 PO 4 . The enhanced activity of the Ag 3 PO 4 /SnO 2 /porcine bone composite may be attributed to the synergistic effect including the matched energy band structures of Ag 3 PO 4 and SnO 2 for the decrease in the probability of electron-hole recombination and improved performance in the presence of hierarchical porous porcine bone (hydroxyapatite). This paper also analyzed the change of the molecular weight and structure of sodium lignin sulfonate in the photocatalytic reaction and discussed the possible photocatalytic mechanism of the photocatalyst composite, indicating that the benzene rings of guaiacol were oxidized into different alkyl acids (maleic acid, oxalic acid, formic acid and methoxy acetic acid).

Lignin Degradation and Its Use in Signaling Development by the Coprophilous Ascomycete Podospora anserina

“…The soluble lignin (Sigma Aldrich cat n° 471003) UV-absorption spectrum was simple in shape and it contained two weak asymmetrical bands: the first was in the region of 210–230 nm, the second with a maximum at 280 nm. This second band indicates the presence of benzene rings in the molecule [ 46 ]. On the day of inoculation by the wild-type strain, the lignin concentration, based on the calculation of the molar extinction coefficient ( Figure S1 ), is equal to 20 µM.…”

Construction of Ag3PO4/SnO2 Heterojunction on Carbon Cloth with Enhanced Visible Light Photocatalytic Degradation

“…Based on the experimental results above, a possible mechanism for highly efficient electron-hole separation is proposed, to explain the improved visible light photocatalytic properties of the Ag3PO4/SnO2/CC sample, as illustrated in Figure 10. The band structure of Ag3PO4 and SnO2 in the figure is drawn based on the data previously reported in other papers [36,38,51,53,54]. For the Ag3PO4/SnO2/CC heterojunction, the conduction band (CB) and valence band (VB) edge potentials of Ag3PO4 are more negative than that of SnO2 [36].…”

“…Due to its good conductivity and stability, SnO 2 is often combined with other semiconductors to form heterojunction, which promotes the separation of photogenerated electron-hole pairs [33][34][35]. For example, Ag 3 PO 4 /SnO 2 [36,37], Ag 3 PO 4 /SnO 2 /porcine bone [38], AgCl/SnO 2 [39] and Ag/AgCl/SnO 2 [40], show enhanced photocatalytic activity over a single photocatalyst.…”

Role of β-CD Macromolecule Anchored to α-Fe2O3/TiO2 on the Selectivity and Partial Oxidation of Guaiacol to Add-Value Products

“…However, improving the selectivity of the photocatalyst to avoid the mineralization of the organic molecules is a key challenge. In this sense, few works have reported on the degradation of guaiacol to carboxylic acids or mineralization and they do not promote the selective oxidation to aromatic organics. − …”