CO2 conversion to solar fuels/chemicals is an alluring approach for narrowing critical issues of global warming, environmental pollution, and climate change, caused by excess atmospheric CO2 concentration. Amongst various CO2 conversion strategies, photocatalytic CO2 conversion (PCC) is considered as a promising approach, which utilizes inexpensive sunlight and water with a photocatalyst material. Hence, development of an efficient and a stable photocatalyst is an essential activity for the respective scientific community to upscale the PCC research domain. Until today, metal oxides, such as TiO2, ZnO, etc., are categorized as standard photocatalysts because of their relative stability, abundant availability and low cost. However, their performance is tethered by limited light absorption and somewhat physical properties. Recently, layered double hydroxides (LDHs) have offered an exciting and efficient way for PCC due to their superb CO2 adsorption and moderate photocatalytic properties. The LDH based photocatalysts show marvelous physiochemical and electrical properties like high surface area, stability, and excellent conductivity. In the present review article, a summarized survey is portrayed regarding latest development for LDH based photocatalysts with a focus on synthesis strategies employing various photocatalyst materials, influencing parameters and possible mechanism involved in PCC to useful fuels and chemicals like CO, CH4, CH3OH, and H2.

A new set of actively cooled toroidal double-ring graphite limiters has been developed in the Hefei Tokamak-7 ͑HT-7͒ ͓X. Gao et al., Phys. Plasmas 7, 2933 ͑2000͔͒ for long pulse operation. The extension of operational region and density behavior with graphite ͑C͒ limiters have been studied in this paper. Extended high-density region at the high plasma current low-q a was obtained. The density profile with the C limiter was studied to compare with the previous molybdenum ͑Mo͒ limiter. The critical density of multifaceted asymmetric radiation from the edge ͑MARFE͒ onset is observed in the region of Z ef f 1/2 f GW = 0.9ϳ 1.2, where f GW = n e / n GW . ͑Here n e is the maximum line average electron density and n GW is the Greenwald density.͒ Under the same injected power, the critical density of MARFE onset with the new C limiter is much higher than the previous Mo limiter.

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Jeans instability is examined in detail in uniform dusty magnetoplasmas taking care of collisional and non-zero finite thermal effects in addition to the quantum characteristics arising through the Bohm potential and the Fermi degenerate pressure using the quantum hydrodynamic model of plasmas. It is found that the presence of the dust-lower-hybrid wave, collisional effects of plasma species, thermal effects of electrons, and the quantum mechanical effects of electrons have significance over the Jeans instability. Here, we have pointed out a new class of dissipative instability in quantum plasma regime.