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Searching for economical low-dimensional materials to construct the highly efficient type-II heterojunction photocatalysts for splitting water into hydrogen is very strategic. In this study, using the first-principles calculations, we construct a novel SiH/CeO2(111) type-II heterojunction with a very small lattice mismatch of less than 1%. Based on AIMD simulation and phonon dispersion calculations, the SiH/CeO2(111) heterojunction reveals sufficient stability, and is easy to synthesize. Due to the vdW interaction between SiH and CeO2(111) components, electron and hole accumulation regions form at the heterojunction interface, which is very conducive to the separation of photoexcited electron–hole pairs. Besides, the SiH/CeO2(111) heterojunction has good visible light response, and even a strong absorption peak of up to 8.7 × 105 cm−1 in the high-energy visible region. More importantly, the SiH/CeO2(111) heterojunction exhibits good OER and HER performance because its oxidation and reduction potentials well meet the requirements of water splitting. Consequently, SiH/CeO2(111) is a potential photocatalyst for splitting water to hydrogen. [ABSTRACT FROM AUTHOR]

Exploring simple, efficient and low cost photocatalysts for hydrogen production driven by visible light is a hot topic in the field of photocatalysis. Here, we study a two-dimensional (2D) layered SiC/C2N van der Waals heterostructure as a possible visible light photocatalyst for water splitting, using hybrid density functional theory calculations. We find that the heterostructure composed of SiC and C2N is a type II heterostructure with a mild band gap (1.58 eV), which can promote the effective separation of electron–hole pairs, thereby suppressing the recombination of photogenerated carriers. The phonon dispersion and ab initio molecular dynamics analysis indicate its good kinetic and thermodynamic stability. Remarkably, atomic projection density of states and energy band structure show that the valence band maximum (VBM) and conduction band minimum (CBM) of the SiC/C2N heterostructure are provided by SiC and C2N, respectively. And its band edge meets the requirements of the redox potential for water splitting. In addition, as the SiC-based heterostructure can retain the excellent visible light performance of the C2N component, it laid the foundation for designing visible-light-driven SiC/C2N photocatalysts. This work may provide valuable information for experimenters to design type II heterostructure photocatalytic materials for water splitting. [ABSTRACT FROM AUTHOR]

Ceria-supported Pd single-atom catalysts (SACs) are important catalysts to catalyze the CO oxidation, often used in three-way catalysts to treat automobile exhaust gases. This paper uses density functional theory (DFT) calculations and transition state theory to systematically study the effect of Ga atom doping on the performance of the Pd/CeO 2 SACs system. Noticeably, the results of DFT calculations reveal that the stability of Pd single atoms supported on the surface of CeO 2 (111) was significantly augmented by doping Ga. An oxygen vacancy generated easily near the Ga and Pd site will act as a crucial role for activating the adsorbed oxygen molecule. Most importantly, the climbing image nudged elastic band (CINEB) calculations show that the doping of Ga remarkably reduces the highest energy barrier during the CO oxidation reaction, meaning that the catalytic performance of the CO oxidation reaction is promoted effectively. This work provides a new perspective for SACs modification. [Display omitted] • Ga-doped Pd/CeO 2 single-atom catalysts with oxygen vacancies are studied in detail. • The stability of Pd single-atom has been enhanced by doping Ga. • O 2 can be further activated at the oxygen vacancies formed by doping Ga. • Ga-doped Pd/CeO 2 possesses higher catalytic activity for CO oxidation. [ABSTRACT FROM AUTHOR]

Searching for economical low-dimensional materials to construct the highly efficient type-II heterojunction photocatalysts for splitting water into hydrogen is very strategic. In this study, using the first-principles calculations, we construct a novel SiH/CeO2(111) type-II heterojunction with a very small lattice mismatch of less than 1%. Based on AIMD simulation and phonon dispersion calculations, the SiH/CeO2(111) heterojunction reveals sufficient stability, and is easy to synthesize. Due to the vdW interaction between SiH and CeO2(111) components, electron and hole accumulation regions form at the heterojunction interface, which is very conducive to the separation of photoexcited electron-hole pairs. Besides, the SiH/CeO2(111) heterojunction has good visible light response, and even a strong absorption peak of up to 8.7 × 105 cm-1 in the high-energy visible region. More importantly, the SiH/CeO2(111) heterojunction exhibits good OER and HER performance because its oxidation and reduction potentials well meet the requirements of water splitting. Consequently, SiH/CeO2(111) is a potential photocatalyst for splitting water to hydrogen.