alternative clean energy supplies and pollution-free technologies turns out to be high priority. [1,2] The CO 2 reduction project plays a pivotal role in response to the concerns because of its capability of exhausted gas consumption and combustible fuels generation. [3][4][5][6] Gas-phase thermal reduction of CO 2 to CO via endothermic reverse water gas shift (RWGS) reaction becomes an attractive strategy on account of abundant accessibility of thermal catalytic active sites. On the same time removing excessive CO 2 in atmosphere, the emitted CO can be also utilized directly as the feedstock for further fuel manufacturing (e.g., via the Fischer-Tropsch process). [7][8][9][10] However, to achieve purposeful CO 2 conversion, massive nonrenewable energy is indispensable to be invested in the reaction. Compared with traditional energy, alternative inexhaustible energy input has been discovered via photothermal process which effectively utilizes full spectrum of sunlight to lead accurate heating location and instantaneously raise the surface temperature of the catalysts. [11][12][13][14][15][16] Indium-oxide-based materials are a typical thermal catalyst with potential prospect for photothermal reduction of CO 2 . Its catalytic active sites promote the adsorption and activation for thermochemical CO 2 hydrogenation, [17,18] but the wide band (2.8 eV) is unfavorable for photothermal conversion for a long time. In order to expanding the limited optical adsorption of In 2 O 3 under sunlight, there have been persistent efforts to alter the material composition of In 2 O 3 , such as element doping, [19] precious metals supporting, [20] and nanostructured substance coating. [21] For example, when Bi metallic dopants are introduced, the optical adsorption can be modified as the result of electronic hybridization between Bi 6s and O 2p orbitals, upwardly shifting the valence band (VB) and consequently reducing bandgap. [22] Recently, Ozin group report a hybrid catalyst consisting of a vertically aligned silicon nanowire (SiNW) support evenly coated by In 2 O 3−x (OH) y nanoparticles to minimized reflection losses and enhanced light trapping within the SiNW support. [23] Basically, eminent photothermal catalysts are composite materials, but the pure ones have not come up yet. In order to construct various active sites to activate wide range of reactants, designing and modulating Photothermal CO 2 reduction technology has attracted tremendous interest as a solution for the greenhouse effect and energy crisis, and thereby it plays a critical role in solving environmental problems and generating economic benefits. In 2 O 3−x has emerged as a potential photothermal catalyst for CO 2 conversion into CO via the light-driven reverse water gas shift reaction. However, it is still a challenge to modulate the structural and electronic characteristics of In 2 O 3 to enhance photothermocatalytic activity synergistically. In this work, a novel route to activate inert In(OH) 3 into 2D black In 2 O 3−x nanosheets via photoinduced defect eng...

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The transformation of CO 2 into a single product is a critical scientific challenge because of the difficulty associated with targeted activation and conversion of CO 2 by heterogeneous catalysts. Herein, we present an atomic-scale dispersed Co−N species anchored Co@C hybrid structure (entitled as Co@ CoN&C) that regulates catalytic properties in thermodynamic and kinetic processes to achieve active and highly selective CO yield in the photothermal CO 2 reduction. An optimal sample delivers the maximum yield rate of 132 mmol g cat.−1 h −1 and remarkable CO selectivity (91.1%), while the undesirable methanation activity, compared with typical Co nanoparticles (NPs), was suppressed. The mechanism study suggests that the strong photon−matter interaction over graphitic-carbon and Co NPs can enhance the light-to-heat conversion efficiency and thus induce the high work temperature, which is thermodynamically beneficial for CO 2 activation and subsequently promoted the catalytic activity. Furthermore, the carbon layers improve the adsorption of CO 2 , and the surface atomically dispersed Co−N species weakens hydrogenation capability, which kinetically controls the reaction pathway and therefore attains the high selectivity for CO production. This study exemplifies that the microstructure design can modulate the thermodynamic and kinetic factors of photochemical reaction and thereby achieve potential solar-to-chemical energy conversion.

Oxygen evolution electrode is a crucial component of efficient photovoltaic‐water electrolysis systems. Previous work focuses mainly on the effect of electronic structure modulation on the oxygen evolution reaction (OER) performance of 3d‐transition‐metal‐based electrocatalyst. However, high‐atomic‐number W‐based compound with complex electronic structure for versatile modulation is seldom explored because of its instability in OER‐favorable alkaline solution. Here, codoping induced electronic structure modulation generates a beneficial effect of transforming the alkaline‐labile WO 2.72 (WO) in to efficient alkaline‐solution‐stable Co and Fe codoped WO 2.72 (Co&Fe‐WO) with porous urchin‐like structure. The codoping lowers the chemical valence of W to ensure the durability of W‐based catalyst, improves the electron‐withdrawing capability of W and O to stabilize the Co and Fe in OER‐favorable high valence state, and enriches the surface hydroxyls, which act as reactive sites. The Co&Fe‐WO shows ultralow overpotential (226 mV, J = 10 mA cm −2 ), low Tafel slope (33.7 mV dec −1 ), and good conductivity. This catalyst is finally applied to a photovoltaic‐water splitting system to stably produce hydrogen for 50 h at a high solar‐to‐hydrogen efficiency of 16.9%. This work highlights the impressive effect of electronic structure modulation on W‐based catalyst, and may inspire the modification of potential but unstable catalyst for solar energy conversion.

Higher-order topological insulator (HOTI) represents a new phase of matter, the characterization of which goes beyond the conventional bulk-boundary correspondence and is attracting significant attention by the broad community. Using a square-root operation, it has been suggested that a square-root HOTI may emerge in a hybrid honeycomb-kagome lattice.Here, we report the first experimental realization of the square-root HOTI in topological LC circuits. We show theoretically and experimentally that the square-root HOTI inherits the feature of wave function from its parent with corner states pinned to nonzero energies. The topological feature is fully characterized by the bulk polarization. To directly measure the finite-energy corner modes, we introduce extra grounded inductors to each node, which shifts corner states to zero-energy without affecting their spatial distributions. Our results experimentally substantiate the emerging square-root HOTI and pave the way to realizing exotic topological phases that are challenging to observe in condensed matter physics.