Single Component Organic Photosensitizer with NIR-I Emission Realizing Type-I Photodynamic and GSH-Depletion Caused Ferroptosis Synergistic Theranostics.

Phototheranostic agents have thrived as prominent tools for tumor luminescence imaging and therapies. Herein, a series of organic photosensitizers (PSs) with donor-acceptors (D-A) are elaborately designed and synthesized. In particular, PPR-2CN exhibits stable near infrared-I (NIR-I) emission, excellent free radicals generation and phototoxicity. Experimental analysis and calculations imply that a small singlet-triplet energy gap (ΔES1-T1 ) and large spin-orbit coupling (SOC) constant boost the intersystem crossing (ISC), leading to type-I photodynamic therapy (PDT). Additionally, the specific glutamate (Glu) and glutathione (GSH) consumption abilities of PPR-2CN inhibit the intracellular biosynthesis of GSH, resulting in redox dyshomeostasis and GSH-depletion causing ferroptosis. This work first realizes that single component organic PS could be simultaneously used as a type-I photodynamic agent and metal-free ferroptosis inducer for NIR-I imaging-guided multimodal synergistic therapy.

Activating Octahedral Center in Co-Doped NiFe2 O4 via Bridging Amorphous MoSx for Electrocatalytic Water Oxidation: A Case for eg Orbital Regulation in Spinel Oxide.

Moderate eg filling for octahedral metal cations (MOh ) is strongly correlated with the electrocatalytic water oxidation performance in the oxides system. Here, the eg fillings of NiOh and FeOh in NiFe2 O4 -based spinel are controllably regulated by introducing an external radical of catalytically inactive MoSx as an electron acceptor via a novel ultrasonic anchored pyrolysis strategy. The electron occupied in eg orbit of MOh emigrates with the amount of MoS hanging on the apical of octahedral sites, and results in a salutary transition from high to medium eg occupancy state, as confirmed by the X-ray absorption spectroscopy and X-ray photoelectron spectroscopy. In addition, benefiting from the abundant unsaturated S atoms in amorphous MoSx , the MOh at the surface furthest activates and consequently shows a superior water oxidation performance. Density functional theory also reveals that the eg fillings of Ni and Fe decrease to 1.4 and 1.2 after MoSx modification, which can effectively reduce the free energy of the OOH* intermediates in the oxygen evolution reaction process. This work opens an avenue for further releasing the electrocatalytic activity of octahedral sites through bridging external phases with rational electron-capturing/donating capability.

Modulating Ti t2g Orbital Occupancy in a Cu/TiO2 Composite for Selective Photocatalytic CO2 Reduction to CO.

The electronic structure of composites plays a critical role in photocatalytic conversion, whereas it is challenging to modulate the orbital for an efficient catalyst. Herein, we regulated the t2g orbital occupancy state of Ti to realize efficient CO2 conversion by adjusting the amount of photo-deposited Cu in the Cu/TiO2 composite. For the optimal sample, considerable electrons transfer from the Cu d orbital to the Ti t2g orbital, as proven by X-ray absorption spectroscopy. The Raman spectra results also corroborate the electron enrichment on the Ti t2g orbital. Further theoretical calculations suggested that the orbital energy of the Ti 3d orbital in TiO2 is declined, contributing to accepting Cu 3d electrons. As a result, the Cu/TiO2 composite exhibited an extremely high selectivity of 95.9 % for CO, and the productivity was 15.27 µmol g-1 h-1 , which is almost 6 times that of the original TiO2 . Our work provides a strategy for designing efficient photocatalysis as a function of orbital regulation.

Tuning W18O49/Cu2O{111} Interfaces for the Highly Selective CO2 Photocatalytic Conversion to CH4.

As a multiple proton-coupled electron transfer process, photocatalytic conversion of CO2 usually produces a wide variety of products. Improving the yield and selectivity of CO2 to the single product is still a significant challenge. In this work, we describe that the rationally constructed W18O49/Cu2O{111} interfaces achieve highly selective CO2 photocatalytic conversion to CH4. In situ Fourier transform infrared spectroscopy measurements reveal that the formation of W18O49/Cu2O{111} interfaces restrains the desorption of CO* intermediates in CO2 photocatalytic conversion. UPS spectra, PL spectra, and photocurrent curves show that more photogenerated electrons are excited and transferred to W18O49/Cu2O{111} interfaces. All of these play critical roles in CH4 production. As an outcome, the yield rate of CO2 photocatalytic conversion to CH4 was enhanced from 6.5 to 17.20 µmol g-1 h-1 with selectivity as high as 94.7%. The work demonstrates the feasibility and versatility of interface engineering in achieving highly selective CO2 photocatalytic conversion.