Photocatalytic formation of hydrocarbons using solar energy via artificial photosynthesis is a highly desirable renewable-energy source for replacing conventional fossil fuels. Using an l-cysteine-based hydrothermal process, here we synthesize a carbon-doped SnS2 (SnS2-C) metal dichalcogenide nanostructure, which exhibits a highly active and selective photocatalytic conversion of CO2 to hydrocarbons under visible-light. The interstitial carbon doping induced microstrain in the SnS2 lattice, resulting in different photophysical properties as compared with undoped SnS2. This SnS2-C photocatalyst significantly enhances the CO2 reduction activity under visible light, attaining a photochemical quantum efficiency of above 0.7%. The SnS2-C photocatalyst represents an important contribution towards high quantum efficiency artificial photosynthesis based on gas phase photocatalytic CO2 reduction under visible light, where the in situ carbon-doped SnS2 nanostructure improves the stability and the light harvesting and charge separation efficiency, and significantly enhances the photocatalytic activity.

No abstract

No abstract

No abstract

Ascertaining the function of in-plane intrinsic defects and edge atoms is necessary for developing efficient low-dimensional photocatalysts. We report the wireless photocatalytic CO2 reduction to CH4 over reconstructed edge atoms of monolayer 2H-WSe2 artificial leaves. Our first-principles calculations demonstrate that reconstructed and imperfect edge configurations enable CO2 binding to form linear and bent molecules. Experimental results show that the solar-to-fuel quantum efficiency is a reciprocal function of the flake size. It also indicates that the consumed electron rate per edge atom is two orders of magnitude larger than the in-plane intrinsic defects. Further, nanoscale redox mapping at the monolayer WSe2–liquid interface confirms that the edge is the most preferred region for charge transfer. Our results pave the way for designing a new class of monolayer transition metal dichalcogenides with reconstructed edges as a non-precious co-catalyst for wired or wireless hydrogen evolution or CO2 reduction reactions.

The residue of antibiotics in the water has led to increased antibioticresistant bacteria, harm to human health, and damage to health-beneficial healthy bacteria. An idea of constructing S-scheme α-Fe 2 O 3 /g-C 3 N 4 nanocomposites is studied toward a photocatalysis application for an efficient resolution of commercial antibiotics in wastewater. Outstanding S-scheme Fe 2 O 3 /g-C 3 N 4 nanocatalysts are synthesized by a straightforward method and could easily improve the recycling property, thanks to magnetic materials. Empirical results indicate that S-scheme Fe 2 O 3 /g-C 3 N 4 photocatalysts can degrade commercial cefalexin and amoxicillin (20 mg L −1 ) under visible light, with five and nine times higher performance than that of g-C 3 N 4 , respectively. Furthermore, the detailed evidence to propose S-scheme Fe 2 O 3 /g-C 3 N 4 heterojunctions and comparison of photocatalytic performance in antibiotic degradation have also been mentioned in this study. KEYWORDS: α-Fe 2 O 3 , g-C 3 N 4 , photocatalysis, α-Fe 2 O 3 /g-C 3 N 4 , S-scheme, antibiotic degradation

No abstract

We report the phase evolution and thermoelectric properties of a series of Co­(Ge0.5Te0.5)3–x Sb x (x = 0–0.20) compositions synthesized by mechanical alloying. Pristine ternary Co­(Ge0.5Te0.5)3 skutterudite crystallizes in the rhombohedral symmetry (R3̅), and Sb doping induces a structural transition to the cubic phase (ideal skutterudite, Im3̅). The Sb substitution increases the carrier concentration while maintaining a high thermopower even at higher doping levels owing to an increased effective mass. The exceptional electronic properties exhibited by Co­(Ge0.5Te0.5)3 upon doping are attributed to the carrier transport from both the primary and secondary conduction bands, as shown by theoretical calculations. The enhanced electrical conductivity and high thermopower increase the power factor by more than 20 times. Because the dominant phonon propagation modes in binary skutterudites are associated with the vibrations of pnictogen rings, twisting the latter through the isoelectronic replacement of Sb4 rings with Ge2Te2 ones, as done in this study, can effectively reduce the thermal conductivity. This leads to an increase in the dimensionless figure-of-merit (zT) by a factor of 30, reaching 0.65 at 723 K for Co­(Ge0.5Te0.5)2.9Sb0.1.