ABSTRACT
Solar-powered photocatalytic conversion of CO2 to hydrocarbon fuels represents an emerging approach to solving the greenhouse effect. However, low charge separation efficiency, deficiency of surface catalytic active sites, and sluggish charge-transfer kinetics, together with the complicated reaction pathway, concurrently hinder the CO2 reduction. Herein, we show the rational construction of transition metal chalcogenides (TMCs) heterostructure CO2 reduction photosystems, wherein the TMC substrate is tightly integrated with amorphous oxygen-containing cobalt sulfide (CoSOH) by a solid non-conjugated polymer, i.e., poly(vinyl alcohol) (PVA), to customize the unidirectional charge-transfer pathway. In this well-defined multilayered nanoarchitecture, the PVA interim layer intercalated between TMCs and CoSOH acts as a hole-relaying mediator and meanwhile boosts CO2 adsorption capacity, while CoSOH functions as a terminal hole-collecting reservoir, stimulating the charge transport kinetics and boosting the charge separation over TMCs. This peculiar interface configuration and charge transport characteristics endow TMC/PVA/CoSOH heterostructures with significantly enhanced visible-light-driven photoactivity and CO2 conversion. Based on the intermediates probed during the photocatalytic CO2 reduction reaction, the photocatalytic mechanism was determined. Our work would inspire sparkling ideas to mediate the charge transfer over semiconductor for solar carbon neutral conversion.
ABSTRACT
<p><b>BACKGROUND</b>In the chronic stage of cerebral venous sinus thrombosis (CVST), recanalization can result in disparate MR appearances. We aimed to prospectively investigate the diagnostic accuracy of magnetic resonance venography (MRV) in the evaluation of the recanalization of CVST.</p><p><b>METHODS</b>This study prospectively evaluated the diagnostic performance of 2-dimensional time-of-flight (2D-TOF) MRV in thirty-two consecutive patients during a three- to six-month follow-up for CVST. Both 2D-TOF MRV and digital substraction angiography (DSA) were undertaken. Diagnostic accuracy of 2D-TOF MRV in the detection of recanalized thrombus was evaluated using DSA as the reference standard.</p><p><b>RESULTS</b>MRV and DSA were completed without complications in all 32 patients. The sensitivity, specificity, positive predictive value, and negative predictive value of 2D-TOF MRV for the detection of recanalization on a segmental basis were 91% (62/68), 93% (37/40), 95% (62/65), and 86% (37/43) respectively.</p><p><b>CONCLUSION</b>2D-TOF MRV provides high sensitivity and specificity for the diagnosis of recanalized CVST segments.</p>