An Exceptionally Efficient Co−Co₂P@N, P‐Codoped Carbon Hybrid Catalyst for Visible Light‐Driven CO₂‐to‐CO Conversion

Abstract

Artificial photosynthesis has attracted wide attention, particularly the development of efficient solar light-driven methods to reduce CO to form energy-rich carbon-based products. Because CO reduction is an uphill process with a large energy barrier, suitable catalysts are necessary to achieve this transformation. In addition, CO adsorption on a catalyst and proton transfer to CO are two important factors for the conversion reaction, and catalysts with high surface area and more active sites are required to improve the efficiency of CO reduction. Here, a visible light-driven system for CO -to-CO conversion is reported, which consists of a heterogeneous hybrid catalyst of Co and Co P nanoparticles embedded in carbon nanolayers codoped with N and P (Co-Co P@NPC) and a homogeneous Ru -based complex photosensitizer. The average generation rate of CO of the system was up to 35 000 μmol h g with selectivity of 79.1 % in 3 h. Linear CO production at an exceptionally high rate of 63 000 μmol h g was observed in the first hour of reaction. Inspired by this highly active catalyst, Co@NC and Co P@NPC materials were also synthesized and their structure, morphology, and catalytic properties for CO photoreduction were explored. The results showed that the nanoparticle size, partially adsorbed H O molecules on the catalyst surface, and the hybrid nature of the systems influenced their photocatalytic CO reduction performance.

Dispersed Nickel Cobalt Oxyphosphide Nanoparticles Confined in Multichannel Hollow Carbon Fibers for Photocatalytic CO2 Reduction

“…[20] In the P2pspectrum (Figure S3 c, Supporting Information), the doublet peaks represent P2 p 3/2 (129.5 eV) and P2 p 1/2 (130.4 eV), while the peak at around 133.0 eV belongs to the PÀOb onds. [30,31] Moreover,t he Co 2p and Ni 2p spectra indicate the coexistence of two solid redox couples (i.e., Ni 2+ /Ni 3+ and Co 2+ / Co 3+ )i nt he sample ( Figure S3 d,e,S upporting Information), [32] which may endow the material with high redox capability for heterogeneous catalysis.A ll these results indicate the successful formation of the mixed metal oxyphosphides.…”

“…[23,24] In addition, hollow structured photocatalysts could utilize the sunlight more efficiently because of the reflection and scattering effects in the interior void. [22,[25][26][27] Although ah andful of single metal phosphides have shown the opportunity for photocatalytic CO 2 reduction reactions, [28][29][30] the application of mixed metal oxyphosphides with tailored structures and compositions in reductive CO 2 photoconversion is still much less reported. Herein, we demonstrate the design and synthesis of nickel cobalt oxyphosphide NPs (NiCoOP NPs) confined in multichannel hollow carbon fibers (MHCFs) for efficient photochemical CO 2 reduction with visible light.…”

“…This gives an atomic Ni percentage of about 6.6 %, which is close to 4.7 %inthe salt precursors.T odetermine the valence state of elements in NiCoOP-NPs@MHCFs,X -ray photoelectron spectroscopy (XPS) characterizations were carried out. TheC1s XPS spectrum can be fitted into three peaks at 284.6, 286.0, and 287.9 eV,c orresponding to the CÀC, CÀO, and C=Ob onds, [30] respectively (Figure S3 a, Supporting Information). Thet hree oxygen peaks with the binding…”

Dispersed Nickel Cobalt Oxyphosphide Nanoparticles Confined in Multichannel Hollow Carbon Fibers for Photocatalytic CO2 Reduction

“…Although a handful of single metal phosphides have shown the opportunity for photocatalytic CO 2 reduction reactions, the application of mixed metal oxyphosphides with tailored structures and compositions in reductive CO 2 photoconversion is still much less reported. Herein, we demonstrate the design and synthesis of nickel cobalt oxyphosphide NPs (NiCoOP NPs) confined in multichannel hollow carbon fibers (MHCFs) for efficient photochemical CO 2 reduction with visible light.…”

“…To determine the valence state of elements in NiCoOP‐NPs@MHCFs, X‐ray photoelectron spectroscopy (XPS) characterizations were carried out. The C 1s XPS spectrum can be fitted into three peaks at 284.6, 286.0, and 287.9 eV, corresponding to the C−C, C−O, and C=O bonds, respectively (Figure S3 a, Supporting Information). The three oxygen peaks with the binding energies of 530.3, 531.7, and 533.0 eV (Figure S3 b, Supporting Information) are correspondingly assigned to the lattice oxygen, the oxygen of hydroxide ions, and the oxygen of physically absorbed water molecules .…”