Effective Driving of Ag-Loaded and Al-Doped SrTiO₃ under Irradiation at λ > 300 nm for the Photocatalytic Conversion of CO₂ by H₂O

Abstract

Al-doped strontium titanite (Al–SrTiO3) containing numerous stepwise edges on the surface was found to exhibit an excellent performance in the photocatalytic conversion of CO2 by H2O as an electron donor under photoirradiation at >300 nm with Ag modification, while in contrast, the Ag-loaded pristine SrTiO3 was inactive as a photocatalyst for this reaction. CO was stably evolved as the main reduction product at a rate of 7.2 μmol h–1 over the Ag-loaded Al–SrTiO3, and a small amount of H2 was generated during the three runs. The selectivity of electrons generated by charge transfer toward CO evolution was ∼98.0%. In addition, the stoichiometric formation of O2 was observed, indicating that H2O acts as an electron donor for the reduction of CO2. Furthermore, isotopic experiments performed using 13CO2 revealed that the CO product is derived from CO2 bubbled into an aqueous solution of NaHCO3 and not from residual carbon species on the catalyst surface.

Optimized Synthesis of Ag‐Modified Al‐Doped SrTiO3 Photocatalyst for the Conversion of CO2 Using H2O as an Electron Donor

“…SEM images of the SrTiO 3 and Al–SrTiO 3 samples prepared at various temperature are shown in Figure . As mentioned in our previous work, many nanosteps appeared on the surface of the sample after doping of Al species into SrTiO 3 . Interestingly, Figures (b)–(f) show that the nanosteps on the surface of the samples became clearer as the calcination temperature increased from 1273 to 1473 K during fabrication.…”

“…The formation rates of H 2 , O 2 , and CO increased with increase in calcination time to 15 h, and the maximum formation rate of CO was achieved at 15 h of calcination time but decreased slightly at higher calcination temperatures. In particular, note that the photocatalytic product (CO) is derived from the CO 2 bubbled through the system rather than other adventitious carbon sources …”

“…As mentioned in the previous works, Al from the environment could influence the ICP‐OES result, which is the reason why 0.76% Al was detected in the pristine SrTiO 3 . Therefore, the value of Al/(Ti + Al) (Table S1 and Figure ) detected by ICP–OES includes background effects . Figure shows the relationship between the CO formation rate and the degree of Al doping.…”

A Water‐Splitting System with a Cobalt (II,III) Oxide Co‐Catalyst‐Loaded Bismuth Vanadate Photoanode Along with an Organo‐Photocathode

“…Water photolysis is known to be the most optimal procedure for acquiring solar hydrogen. Since the discovery of the water splitting system comprising a titanium(IV) dioxide (TiO 2 ) photoanode by Honda and Fujishima, [1] numerous studies on water splitting by both photoelectrochemical and photocatalytic methods have been conducted [2–12] . As a long‐standing issue, the development of active photocatalyst materials, which are able to efficiently utilize the solar spectrum for high output of molecular hydrogen, is required.…”

Tuning the Magnetism in Boron-Doped Strontium Titanate

“…As one of the most famous perovskite ceramic materials, strontium titanate (SrTiO 3 ) has attracted a great deal of attention and led to promising technological applications [ 17 , 18 , 19 , 20 ]. Great efforts have been made to modify the electronic structures of monodoped or codoped SrTiO 3 [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ], e.g., to enhance the visible light photocatalytic activity or for applications in water splitting [ 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 ]. Some researchers have been devoted to manipulating the magnetic properties by doping transition metals into SrTiO 3 both theoretically and experimentally [ 48 , 49 , 50 , 51 , 52 ].…”