The long-chain ligands and weak charge-transport capacity of perovskite nanocrystal (NC) always hinder its optoelectronic applications. Our study proposes an effective strategy to unlock the optimized nonlinear optical (NLO) properties of perovskite via the aromatic ligand-exchange plus porphyrin-axial-coordination. Synthesized porphyrin-pyridine dual-modified CsPbBr3-NC hybrid material, fabricated by 4-(aminomethyl)pyridine (PyMA) and a novel star-shaped zinc-porphyrin trisubstituted triazacoronene compound (ZnPr) modifications, exhibits excellent NLO absorption performance under femtosecond (fs) laser irradiation in the visible to near-infrared range. Specifically, its nonlinear absorption coefficient is 10 times higher than that of the pristine CsPbBr3-NC and it also possesses an outstanding optical limiting (OL) capability with an OL threshold as low as 1.8 mJ cm−2. The modification of PyMA ligands reduces the trap state density on the perovskite surface and promotes the electronic coupling between the NC lattices. With the aid of PyMA coordinating with the Zn atoms in ZnPr, large-size planar porphyrins are anchored on the perovskite surface from the axial position, which may enhance the ligand protection capability and thereby significantly facilitate the charge transport between porphyrin components and perovskite NCs. The above two-step modification synergistically contributes to the prominent NLO performance. Our work affords a new viable paradigm for developing multi-field and high-performance perovskite NC photonic materials and devices.
Hui Yang,Xiangwei Liu,Kang Qin,Qijing Bu,Qingyun Liu
Designing durable, high-active, and low-cost noble-metal-free photoelectrocatalysts for methanol electrooxidation is highly demanded but remains a challenge. Herein, the photoelectrocatalytic activity of cobalt–copper layer double hydroxide (CoCu-LDH) for methanol oxidation reaction (MOR) in the alkaline media under light was remarkably enhanced by cerium (Ce) doping and further by 5,10,15,20-tetrakis(4-carboxylphenyl)porphyrin (TCPP) modification. TCPP/Ce–CoCu-LDH exhibits a remarkable mass activity of 1788.2 mA mg–1 in 1 mol L–1 KOH with 1 mol L–1 methanol under light, which is 2.3 and 1.8 times higher than that of CoCu-LDH (782.2 mA mg–1) and Ce–CoCu-LDH (987.4 mA mg–1). The UV–vis diffuse reflectance spectra and photoluminescence emission spectra reveal that TCPP/Ce–CoCu-LDH can effectively utilize the visible light and inhibit the electron–hole pairs’ recombination because of the introduction of porphyrin. Furthermore, more active sites and the greater electrical conductivity of TCPP/Ce–CoCu-LDH also contributed to the high photoelectrocatalytic activity. Thus, TCPP/Ce–CoCu-LDH can be used as a low-cost alternative for Pt-based catalyst toward MOR.
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