다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Photoreduction of CO2 into sustainable and green solar fuels is generally believed to be an appealing solution to simultaneously overcome both environmental problems and energy crisis. The low selectivity of challenging multi-electron CO2 photoreduction reactions makes it one of the holy grails in heterogeneous photocatalysis. This Review highlights the important roles of cocatalysts in selective photocatalytic CO2 reduction into solar fuels using semiconductor catalysts. A special emphasis in this review is placed on the key role, design considerations and modification strategies of cocatalysts for CO2 photoreduction. Various cocatalysts, such as the biomimetic, metal-based, metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area. This Review provides useful information for the design of highly selective cocatalysts for photo(electro)reduction and electroreduction of CO2 and complements the existing reviews on various semiconductor photocatalysts.

Cocatalysts for Selective Photoreduction of CO2 into Solar Fuels.

Seawater is one of the most abundant natural resources on our planet. Electrolysis of seawater is not only a promising approach to produce clean hydrogen energy, but also of great significance to seawater desalination. The implementation of seawater electrolysis requires robust and efficient electrocatalysts that can sustain seawater splitting without chloride corrosion, especially for the anode. Here we report a three-dimensional core-shell metal-nitride catalyst consisting of NiFeN nanoparticles uniformly decorated on NiMoN nanorods supported on Ni foam, which serves as an eminently active and durable oxygen evolution reaction catalyst for alkaline seawater electrolysis. Combined with an efficient hydrogen evolution reaction catalyst of NiMoN nanorods, we have achieved the industrially required current densities of 500 and 1000 mA cm−2 at record low voltages of 1.608 and 1.709 V, respectively, for overall alkaline seawater splitting at 60 °C. This discovery significantly advances the development of seawater electrolysis for large-scale hydrogen production. Seawater electrolysis is a promising approach to produce hydrogen fuel and is also of great significance to seawater desalination. Here, the authors prepare 3D core-shell metal-nitride catalysts from earth-abundant elements for high-performance alkaline seawater electrolysis.

/pdf/non-noble-metal-nitride-based-electrocatalysts-for-high-4vljz5ryqm.pdf

Non-noble metal-nitride based electrocatalysts for high-performance alkaline seawater electrolysis

Product selectivity of photocatalytic CO2 reduction reactions

Ternary Ni2(1-x)Mo2xP nanowire arrays toward efficient and stable hydrogen evolution electrocatalysis under large-current-density

Water electrolysis utilizing renewable electricity power is a promising technology to produce green hydrogen energy on a large scale. However, this energy conversion technology is seriously hindered by the high activation barrier of the oxygen evolution reaction (OER), which requires highly active and robust electrocatalysts. Herein, we have developed a novel three-dimensional (3D) core–shell OER electrocatalyst, in which defective and ultrathin NiFe layered double hydroxide (NiFe LDH) nanosheets are rationally decorated on V-doped Ni3S2 nanorod arrays supported on Ni foam (V-Ni3S2@NiFe LDH). The highly conductive V-doped Ni3S2 nanorod cores ensure rapid charge transfer, and the ultrathin NiFe LDH nanosheets with rich defects offer numerous exposed active sites, together with the unique 3D core–shell nanostructures that benefit electrolyte diffusion and gas products releasing, thus our hierarchical catalyst is distinguished by very low overpotentials of 209 and 286 mV to obtain current densities of 10 and 100 mA cm−2, respectively, for OER in 1 M KOH. Impressively, when this 3D core–shell catalyst is paired with V-doped Ni3S2 nanorod arrays for overall water splitting, an outstanding two-electrode electrolyzer is achieved, which only requires 1.55 V to deliver a current density of 10 mA cm−2 in 1 M KOH, even superior to the benchmark of RuO2(+)//Pt(−). Our work provides a novel and effective strategy to rationally design efficient 3D hierarchical catalysts for energy conversion and storage.

Defective and ultrathin NiFe LDH nanosheets decorated on V-doped Ni3S2 nanorod arrays: a 3D core–shell electrocatalyst for efficient water oxidation

Photocatalytic reduction of CO2 to CO over copper decorated g-C3N4 nanosheets with enhanced yield and selectivity

Transition-metal sulfides (TMS) have been widely studied for electrocatalytic hydrogen evolution reaction (HER). Nevertheless, the HER activity is still far lower than the benchmark Pt-based materials due to the sparse exposed active sites, poor electron transfer and unsatisfying stability of TMS. In this work, we have successfully prepared N-doped Ni-Mo based sulfide cuboid arrays on Ni foam (denoted as N-NiMoS) towards high-efficiency and long-term HER. Systematic investigations confirm that N doping effectively regulates the electron density and tunes d-band center of NiMoS, which facilitate electron transport and improve electronic conductivity. Additionally, the hierarchical N-NiMoS cuboid arrays present larger surface area with more exposed active sites, thus endowing our catalyst with excellent HER catalytic activity with low overpotentials of 68, 250, and 322 mV at current densities of 10, 500, and 1000 mA cm−2, respectively. Impressively, the N-NiMoS electrode also displays superior stability, with a unattenuated current density over 1000-h HER operation.

N-doped Ni-Mo based sulfides for high-efficiency and stable hydrogen evolution reaction

Developing a facile strategy for universal synthesis of transition metal catalysts is significant to catalytic reactions but remains challenging. Herein, we report an ultrafast one-step electrodeposition method to prepare a series of transition metal foams within one minute for electrocatalytic water splitting. The porous metal foams not only possess unique 3D channels for rapid electrolyte diffusion and gas releasing, but also have robust integrated structures with enhanced conductivity for efficient charge transport. Consequently, the NiCo and NiFe foams only require 86 and 206 mV to output 10 mA cm−2 for hydrogen and oxygen evolution reactions (HER and OER) in 1 M KOH, respectively. Combining the two electrocatalysts, we have assembled an outstanding alkaline electrolyzer, requiring only 1.52 and 1.64 V to deliver 10 and 100 mA cm−2 respectively, outperforming the RuO2(+)//Pt/C(-) electrolyzer. Our study offers an ultrafast and general approach to fabricate 3D porous electrocatalysts for high-performance water splitting.

Jianqing Zhou

Papers

Ternary Ni2(1-x)Mo2xP nanowire arrays toward efficient and stable hydrogen evolution electrocatalysis under large-current-density

Defective and ultrathin NiFe LDH nanosheets decorated on V-doped Ni3S2 nanorod arrays: a 3D core–shell electrocatalyst for efficient water oxidation

Photocatalytic reduction of CO2 to CO over copper decorated g-C3N4 nanosheets with enhanced yield and selectivity

N-doped Ni-Mo based sulfides for high-efficiency and stable hydrogen evolution reaction

Ultrafast fabrication of porous transition metal foams for efficient electrocatalytic water splitting