Overall water splitting by graphdiyne-exfoliated and -sandwiched layered double-hydroxide nanosheet arrays

Abstract

It is of great urgency to develop efficient, cost-effective, stable and industrially applicable electrocatalysts for renewable energy systems. But there are still few candidate materials. Here we show a bifunctional electrocatalyst, comprising graphdiyne-exfoliated and -sandwiched iron/cobalt layered double-hydroxide nanosheet arrays grown on nickel foam, for the oxygen and hydrogen evolution reactions. Theoretical and experimental data revealed that the charge transport kinetics of the structure were superior to iron/cobalt layered double-hydroxide, a prerequisite for improved electrocatalytic performance. The incorporation with graphdiyne increased the number of catalytically active sites and prevented corrosion, leading to greatly enhanced electrocatalytic activity and stability for oxygen evolution reaction, hydrogen evolution reaction, as well as overall water splitting. Our results suggest that the use of graphdiyne might open up new pathways for the design and fabrication of earth-abundant, efficient, functional, and smart electrode materials with practical applications.

Engineering active sites on hierarchical transition bimetal oxides/sulfides heterostructure array enabling robust overall water splitting

“…7b and Supplementary Tabel 7). Compared to the reported electrocatalysts with the large current densities (e.g., 500 and 1000 mA cm −2 ), such as NiMoN@NiFeN 65 , nickel-cobalt complexes hybridized MoS 2 66 , Ni-P-B/paper 49 , NiVIr-LDH ||NiVRu-LDH 50 , phosphorus-doped Fe 3 O 4 51 , graphdiyne-sandwiched layered double-hydroxide nanosheets 67 , N,S-coordinated Ir nanoclusters embedded on N,S-doped graphene 68 , Co 3 Mo/Cu 69 , and FeP/Ni 2 P hybrid 70 , all aforementioned analysis confirm that as-prepared NiMoO x /NiMoS array could be served as promising industrial candidate for overall water splitting. With regard to the operating stability as important metric, this typical two-electrode cell can maintain the excellent electrocatalytic activity at a large current density of 500 mA cm −2 at the voltage of 1.75 V over 500 h without obvious degradation in 1 M KOH solution at 25°C (Fig.…”

Graphene/MoS2/FeCoNi(OH)x and Graphene/MoS2/FeCoNiPx multilayer-stacked vertical nanosheets on carbon fibers for highly efficient overall water splitting

“…Although the FeCoNi(OH) x nanosheets may be the dominant contributor to the high catalytic activity of the CF/VMFO, the role of the MoS 2 nanosheets is especially key. The strategy to improve the performance of electrocatalysts by integrating different materials has been widely used 14 , 42 – 45 . For example, Hui et al prepared iron–cobalt LDH (ICLDH) nanosheet arrays on nickel foam (NF) by hydrothermal treatment and then used hexaethynylbenzene to intercalate into the interlayer space of the iron–cobalt LDH 42 .…”

Efficient Co@Co3O4 core-shell catalysts for photocatalytic water oxidation and its behaviors in two different photocatalytic systems

“…O 2 + 4H + + 4e À ) (E 0 = 1.23 eV) and a half-reaction of reducing water into H 2 (4H + + 4e À ? 2H 2 ) (E 0 = 0.00 eV) [11][12][13]. The energy required for the water oxidation is higher and it is more difficult to perform than the reduction of water, therefore, it is vital to achieve breakthrough in the water oxidation for the overall water splitting, and ultimately achieve efficient water reduction to obtain H 2 [14][15][16][17][18][19][20].…”