Abstract:With the serious worldwide problem of carbon emissions, carbon emissions' control and trade have become necessary policies adopted by the governments, after the establishment of the EU Emissions Trading System (EU ETS), China has also implemented a similar carbon emission trading pilot policy which plays a vital role in environmental regulation and influences enterprise behaviors, so this paper will put more focus on the impact of this policy on the enterprise innovation. In this paper, we construct a theoretical model and use the "Chinese Carbon Emissions Trading Pilot Policy" as a quasi-natural experiment to accurately identify the net causal effect of this environmental policy on enterprise innovation. Moreover, we use the synthetic control and difference-in-differences methods to eliminate the endogeneity to a large extent and conduct the robustness tests, difference-in-differences method, placebo test, and permutation test to respectively confirm these results. The results show that the implementation of carbon emissions trading policy will significantly reduce the enterprise innovation in general, this conclusion is contrary to the EU ETS's effect, which is confirmed by plenty of previous empirical study. However, this policy has different effects across enterprises of different industries and different types of innovation. It can promote enterprise innovation of environmental industry, but it will inhibit enterprise innovation of non-environmental industry; besides, it can promote the development of green technical innovation and inhibit non-green technical innovation, which is basically identical to the causal effect of EU ETS.

No abstract

While the microenvironment around catalytic sites is recognized to be crucial in thermocatalysis, its roles in photocatalysis remain subtle. In this work, a series of sandwich‐structured metal–organic framework (MOF) composites, UiO‐66‐NH2@Pt@UiO‐66‐X (X means functional groups), is rationally constructed for visible‐light photocatalytic H2 production. By varying the ─X groups of the UiO‐66‐X shell, the microenvironment of the Pt sites and photosensitive UiO‐66‐NH2 core can be simultaneously modulated. Significantly, the MOF composites with identical light absorption and Pt loading present distinctly different photocatalytic H2 production rates, following the ─X group sequence of ─H > ─Br > ─NA (naphthalene) > ─OCH3 > ─Cl > ─NO2. UiO‐66‐NH2@Pt@UiO‐66‐H demonstrates H2 production rate up to 2708.2 µmol g−1 h−1, ≈222 times that of UiO‐66‐NH2@Pt@UiO‐66‐NO2. Mechanism investigations suggest that the variation of the ─X group can balance the charge separation of the UiO‐66‐NH2 core and the proton reduction ability of Pt, leading to an optimal activity of UiO‐66‐NH2@Pt@UiO‐66‐H at the equilibrium point.

ZnSe microspheres with various Ag and Mn doping levels were prepared by the hydrothermal method using Zn(NO 3 ) 2 ·6H 2 O and Na 2 SeO 3 as precursors and N 2 H 4 ·H 2 O as the reducing agent. The effects of Ag and Mn doping on the phase composition, morphology, and optical and electrical properties of the final products were systematically investigated. A remarkable change in morphology from microspheres with a cubic sphalerite structure to rodlike structure was observed by Ag doping, while the pristine structure was nearly unchanged via Mn doping. Moreover, the band gap of ZnSe microspheres could be tunable in a broad range via controlling the Ag and Mn doping concentration, and ZnSe with high electrical properties could be obtained by doping with an appropriate concentration. The first-principle plane-wave method was carried out to explain the above mentioned experimental results.