Silver Single Atom in Carbon Nitride Catalyst for Highly Efficient Photocatalytic Hydrogen Evolution

Abstract

Single atom catalysts (SACs) with the maximized metal atom efficiency have sparked great attention. However, it is challenging to obtain SACs with high metal loading, high catalytic activity, and good stability. Herein, we demonstrate a new strategy to develop a highly active and stable Ag single atom in carbon nitride (Ag‐N2C2/CN) catalyst with a unique coordination. The Ag atomic dispersion and Ag‐N2C2 configuration have been identified by aberration‐correction high‐angle‐annular‐dark‐field scanning transmission electron microscopy (AC‐HAADF‐STEM) and extended X‐ray absorption. Experiments and DFT calculations further verify that Ag‐N2C2 can reduce the H2 evolution barrier, expand the light absorption range, and improve the charge transfer of CN. As a result, the Ag‐N2C2/CN catalyst exhibits much better H2 evolution activity than the N‐coordinated Ag single atom in CN (Ag‐N4/CN), and is even superior to the Pt nanoparticle‐loaded CN (PtNP/CN). This work provides a new idea for the design and synthesis of SACs with novel configurations and excellent catalytic activity and durability.

Single-atom Cu anchored catalysts for photocatalytic renewable H2 production with a quantum efficiency of 56%

“…The carrier lifetime of TiO 2 and CuSA-TiO 2 were determined to be 3.82 ns and 2.04 ns, respectively. The CuSA-TiO 2 shows a shorter PL lifetime compared to that of TiO 2 , revealing the faster electron transfer in CuSA-TiO 2 22,44 .…”

“…However, the aggregation of SACs is inevitable during the catalytic reaction due to their high surface energy or leaching due to the unstable anchoring as the majority were synthesized by post-treatment (e.g., impregnation approach) [19][20][21] . More importantly, the larger the percentage of SACs, the higher the activity, whereas to load higher than 0.5 wt% of SACs is very challenging as the majority of the studies reported a limited amount of SACs (usually near 0.1-0.3 wt %) 1,2 onto the high surface area of substrates and it is difficult to control and reproduce 4,22,23 . Hence, obtaining the highly dispersed and high concentration of SACs remains to be the main bottleneck in photocatalytic H 2 production.…”

Anchoring Copper Single Atoms on Porous Boron Nitride Nanofiber to Boost Selective Reduction of Nitroaromatics

“…To date, various SACs have been synthesized via anchoring single metal atoms on numerous materials [7][8][9][10][11][12][13] . Isolated metal atoms are generally stabilized by surface oxo ligands 14,15 , defects (vacancies and monoatomic step edges) [16][17][18][19] , heteroatoms [20][21][22] and con ned space [23][24][25][26] of supporting materials.…”

Efficient Electronic Modulation of g-C 3 N 4 Photocatalyst by Implanting Atomically Dispersed Ag 1 -N 3 for Extremely High Hydrogen Evolution Rates

“…That is to say, the embedded single-atom Ag or Cu into the matrix of g-C 3 N 4 improves the photocatalytic performance of HCNS by adjusting the modulation of electronic structure rather than serving as active sites, which is different from the previously reported results that the introduced single-atom metals acting as active sites. [32][33][34][35][36][37] In addition, the apparent quantum yield (AQY) of Ag 1 N 3 -HCNS is calculated to be about 23.6% at a monochromatic light of 420 nm (Figure 3b). Moreover, the photocatalytic stability of Ag 1 N 3 -HCNS was examined for 52 h with intermittent degassing of the reaction test every 4 h (Supporting Information Figure S10).…”