Intraligand charge transfer boosts visible-light-driven generation of singlet oxygen by metal-organic frameworks

Click Modification of a Metal–Organic Framework for Two-Photon Photodynamic Therapy with Near-Infrared Excitation

“…To verify the type of generated ROS, we performed electron spin resonance (ESR) experiments using 5,5-dimethyl-1-pyrroline- N -oxide (DMPO) and 2,2,6,6-tetramethylpiperidine (TEMP) as the O 2 •– and 1 O 2 trapping agents, respectively. As shown in Figure a, an accordant signal with DMPO-OOH as a spin derivative of DMPO-O 2 •– was obtained (an intense characteristic 1:2:2:1 signal with g || = 2.014, g ⊥ = 2.003 was observed) upon LED light irradiation (LED light, 400–700 nm, 40 mW/cm 2 ), proving the production of O 2 •– . , In addition, in contrast to the negligible ESR signal measured in the dark, the evident DMPO–OOH signal under light irradiation further confirmed the excellent light-induced O 2 •– generation ability of PCN-58-Ps-HA . Then, the characteristic signals due to TEMP induced by 1 O 2 were recorded in an aqueous solution of PCN-58-Ps-HA .…”

“…The generated ROS were confirmed from the participation of the O 2 •– probe dihydrorhodamine 123 (DHR123) and the 1 O 2 probe 1,2-diphenylisobenzofuran (DPBF). With LED light irradiation (400–700 nm, 40 mW/cm 2 ), O 2 •– and 1 O 2 were induced by PCN-58 and Ps , respectively. − Through the fluorescence intensity change for DHR123, the production ability of O 2 •– , which was induced by PCN-58-Ps-HA , was found to be stronger than that of PCN-58 (Figures c and S16). In addition, accompanied by the production of 1 O 2 , the absorbance of DPBF (420 ± 5 nm) decreased gradually.…”

Direct Attack and Indirect Transfer Mechanisms Dominated by Reactive Oxygen Species for Photocatalytic H2O2 Production on g-C3N4 Possessing Nitrogen Vacancies

“…When − and h + on the NV site are very close, so h + may tend to combine with •O 2 − to generate 1 O 2 (eq 6). 58 In contrast, the •O 2 − anchored at the NV 1,4 site is farther from the hole accumulation area, which may reduce the probability of charge recombination and make the •O 2 − at this position more stable (Figure S17a). Based on the results of TDDFT simulation, it can be speculated that the NV site and NV 1,4 site can serve as a charge recombination and reduction center for dioxygen, promoting the generation of •O 2 − and 1 O 2 , respectively.…”

TiO2@MOF Photocatalyst for the Synergetic Oxidation of Microcystin-LR and Reduction of Cr(VI) in Aqueous Media

“…Therefore, the photogenerated holes are enhanced and play the main roles in the synergetic oxidation of MC-LR. Additionally, due to the structure of metal-organic chromophore linkers as a catalytic center in MIL101(Fe) [45], the generation of 1 O2 might originated from the photosensitization of MIL101(Fe)/TiO2 under UV irradiation [57], and is also involved the synergetic degradation reaction. As is demonstrated in the above discussion aabove, the flow pathway of photogenerated e − and the ROS generation mechanism can be clearly verified in MIL-101(Fe)/TiO 2 .…”