Photocatalytic reforming of glucose under visible light over morphology controlled Cu₂O: efficient charge separation by crystal facet engineering

Abstract

Multifaceted Cu2O with controlled crystal facet exposure was synthesized via a facile one-step method. It was found that photogenerated electrons prefer to accumulate on high index planes, while holes tend to migrate to {100} facets of a Cu2O polyhedron, leading to efficient charge separation and enhanced photocatalytic reforming of glucose.

Sonnengetriebene Wasserstofferzeugung aus Lignocellulose

“…Die Verwendung von Pt/CdZnS als Photokatalysator ermçglicht Glucosereformierung unter sichtbarem Licht mit bis zu 0.485 mmol H 2 g cat À1 h À1 , [28] während ZnS/ZnIn 2 S 4 eine geringere Aktivitätz eigt. [29] Unedle Cokatalysatoren sind mitunter leistungsfähiger als Pt, so wie im Falle eines MoS 2 /CdSKompositmaterials, [30] [32] und Fe 2 O 3 /Si (4.42 mmol H 2 g cat À1 h À1 ), [33] eine vielversprechende Aktivitätin der PR von Glucose unter sichtbarem Licht. LaFeO 3 , [34] BiYVO 4 , [35] CaTa 2 O 6 , [36] La:NaTaO 3 , [37] und SrTiO 3 [38] sind weitere Beispiele.…”

Simultaneous Production of CH4and H2from Photocatalytic Reforming of Glucose Aqueous Solution on Sulfated Pd-TiO2Catalysts

“…In the past two decades, photocatalytic processes have been investigated as a possible method to obtain hydrogen glucose aqueous solutions [21]. The photocatalytic hydrogen production by decomposition of water containing glucose seems to have become a very powerful method for the practical and lowcost technologies in the hydrogen based energy system [22,23]. Different catalysts containing noble metals on the surface (Au, Pt, Pd) or nanostructured Fe 2 O 3 polymorphs [24] have been investigated [22,25] because the presence of noble metals on the surface of the semiconductor improves photocatalytic performances.…”

Reduced graphene oxide encapsulated Cu2O with controlled crystallographic facets for enhanced visible-light photocatalytic degradation

“…The surface energy difference between f100g and f111g facets for cuboctahedral Cu 2 O might first drive the separation of photogenerated electron-hole pairs and lead to the aggregation of holes at the f100g facets and electrons at the f111g facets. 17 Therewith, the electrons quickly transfer to conductive rGO sheets, resulting in effective separation of electron-hole pairs 11,14 and further enhancement in the photocatalytic performance of samples, 12 as shown in schematic illustration in Fig. 6(a).…”

“…A weaker peak at around 630 cm À1 can be ascribed to the defects caused from the symmetry destruction of Cu 2 O lattice, 11 and the intensity of defect peak flows in the order of S 2 > S 3 > S 1 . This could be related to the oxygen defect in semiconductor/rGO composite and might be affected by interfacial electronic properties of composites due to the composition difference in the semiconductor 17,18 and be helpful for the enhancement of photocatalytic performance. 19 For the rGO and GO sheets, two main peaks at around 1330 cm À1 and 1595 cm À1 belong to the characteristic signals of disordered sp 2 -hybridized carbon associated with structural defects (D band) and well-order E 2g phonon scattering of sp 2 -hybridized carbon (G band), respectively.…”

“…This hints that the surface energy difference between f100g and f111g facets could serve as a driving force to promote the separation of photogenerated electron-hole pairs. 7,17,18 When rGO sheets are introduced into the system, the Cu 2 O/rGO composite, especially cuboctahedra Cu 2 O/rGO demonstrates the highest photocurrent, hinting its prominent photoelectric conversion effect. The photoluminescence (PL) spectra in Fig.…”