Photocatalytic reduction of low-concentration CO2 by metal-organic frameworks.

Direct conversion of diluted CO2 to value-added chemical stocks and fuels with solar energy is an energy-saving approach to relieve global warming and realize a carbon-neutral cycle. The exploration of catalysts with both efficient CO2 adsorption and reduction ability is significant to achieving this goal. Metal-organic frameworks (MOFs) are emerging in the field of low-concentration CO2 reduction due to their highly tunable structure, high porosity, abundant active sites and excellent CO2 adsorption capacity. This highlight outlines the advantages of MOFs for low-pressure CO2 adsorption and the strategies to improve the photocatalytic performance of MOF materials at low CO2 concentrations, including the functionalization of organic ligands, regulation of metal nodes and preparation of MOF composites or derivatives. This paper aims to provide possible avenues for the rational design and development of catalysts with the ability to reduce low-concentration CO2 efficiently for practical applications.

Transition-Metal-Modified Vanadoborate Clusters as Stable and Efficient Photocatalysts for CO2 Reduction.

Photocatalytic carbon dioxide reduction (CO2RR) is considered to be a promising sustainable and clean approach to solve environmental issues. Polyoxometalates (POMs), with advantages in fast, reversible, and stepwise multiple-electron transfer without changing their structures, have been promising catalysts in various redox reactions. However, their performance is often restricted by poor thermal or chemical stability. In this work, two transition-metal-modified vanadoborate clusters, [Co(en)2]6[V12B18O54(OH)6]·17H2O (V12B18-Co) and [Ni(en)2]6[V12B18O54(OH)6]·17H2O (V12B18-Ni), are reported for photocatalytic CO2 reduction. V12B18-Co and V12B18-Ni can preserve their structures to 200 and 250 °C, respectively, and remain stable in polar organic solvents and a wide range of pH solutions. Under visible-light irradiation, CO2 can be converted into syngas and HCOO- with V12B18-Co or V12B18-Ni as catalysts. The total amount of gaseous products and liquid products for V12B18-Co is up to 9.5 and 0.168 mmol g-1 h-1. Comparing with V12B18-Co, the yield of CO for V12B18-Ni declines by 1.8-fold, while that of HCOO- increases by 35%. The AQY of V12B18-Co and V12B18-Ni is 1.1% and 0.93%, respectively. These values are higher than most of the reported POM materials under similar conditions. The density functional theory (DFT) calculations illuminate the active site of CO2RR and the reduction mechanism. This work provides new insights into the design of stable, high-performance, and low-cost photocatalysts for CO2 reduction.

[Effect of yanggan yishui granule on collagen I, III, and IV, and FN in spontaneously hypertensive rats].

OBJECTIVE: To observe the effect of Yanggan Yishui Granule (YGYSG) on collagen protein I, III, and IV, as well as fibronection (EN) in spontaneously hypertensive rats (SHR), and to explore its possible renal protective mechanisms. METHODS: Fourty SHR were randomly divided into four groups, i.e., the model group, the Benazepril group, the low dose YGYSG group, and the high dose YGYSG group, 10 in each group. A normal control group was set up with recruited Wistar-Kyoto (WKY) rats. After 6 weeks of treatment, the expression of collagen protein I, III, and IV, as well as FN in the 5.1 image analysis system. RESULTS: In the WKY-control group, there was only a small amount of brown particles in the mesenchymal region, the glomerular basement membrane, or the mesangial region. The expression of collagen I, Ill, and IV, as well as EN significantly increased more in the model group than in the normal control group (P < 0.01). After treatment, the expression of collagen I, III, and IV, as well as FN significantly decreased in each treated group, showing statistical difference when compared with the model group (P < 0.01). Besides, decresed expression of collagen I, III, and IV was shown in the low dose YGYSG group and the Benazepril group (P > 0.05). The expression of collagen I, III, and IV could be further reduced in the high dose YGYSG group, showing statistical difference when compared with the Benazepril group and the low dose YGYSG group (P < 0.05, P < 0.01). CONCLUSION: YGYSG might play an important role in the renal protective effect through reducing the synthesis of renal collagen I, III, and IV, as well as FN, increasing the degradation of renal collagen I, III, and IV, as well as FN, thereby reducing excessive deposition of renal extracellular matrix (ECM).