Graphene/reduced graphene oxide (rGO) modification has been demonstrated to be an efficient route to improve the photocatalytic performance of various photocatalysts by promoting the effective separation of photogenerated electrons and holes. It is highly required to develop facile and environmental-friendly methods for the preparation of graphene-based photocatalytic materials. In this study, the Ag/AgCl/rGO heterostructure photocatalyst was fabricated by a mild oxidization reaction of hydrothermally prepared Ag/rGO in FeCl3 solution. It was found that the reduction of graphene oxide (GO) was accompanied with the in situ formation of metallic Ag in a Ag[(NH3)2](+)-immobilized GO solution during hydrothermal treatment, while the following in situ oxidation of metallic Ag by FeCl3 solution resulted in the formation of strongly coupled Ag/AgCl/rGO heterostructure photocatalyst. The photocatalytic experimental results indicated that all the resultant Ag/AgCl/rGO nanocomposite photocatalysts exhibited a much higher photocatalytic activity than the Ag/AgCl and physically mixed Ag/AgCl/rGO composite, and the Ag/AgCl/rGO (3.2 wt % rGO) showed the highest photocatalytic performance. The enhanced photocatalytic performance of Ag/AgCl/rGO heterostructures can be attributed to the cooperation effect of the effective separation of photogenerated carriers via strongly coupled rGO cocatalyst and the enrichment of organic molecules on the rGO nanosheets. Considering the facile preparation and its high photocatalytic activity, it is possible for the present Ag/AgCl/rGO nanocomposites to be widely applied in various fields such as air purification and wastewater treatment.

Benefitting from the strong intrinsic nonlinear optical (NLO) property of the individual porphyrin molecule, the integration of porphyrin molecules into tightly aligned arrays may lead to intuitively promising high-performance materials of tailorable NLO effect. In order to verify this speculation, we prepare crystalline and highly oriented porphyrin-based surface-supported metal–organic framework nanofilms (SURMOFs) and then characterize their NLO performance. Results reveal that porphyrin-based SURMOFs exhibit the highest saturable absorption (SA) yet recorded with a third-order NLO absorption coefficient up to −10–3 cm/W, about 7 orders stronger than porphyrin solvents in which the porphyrin molecules are disordered, under a certain excitation strength. Further increasing the excitation strength shows that the NLO absorption property of the porphyrin-based SURMOFs can be effectively modulated from SA to reverse saturable absorption, followed by a reemerging SA. The multiple-stage NLO switching is assigned to the interplay of simultaneous one-photon SA, two-photon absorption, and two-photon SA effects. The superior and modulatable NLO property as well as the designable and ordered crystalline structure suggest that porphyrin-based SURMOFs might be employed as a new class of high-performance NLO materials with potential applications in novel optical switches or logic gates to realize the all-optical information process.

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