As an important reactive oxygen species (ROS) with selective oxidation, singlet oxygen ( 1 O 2 ) has wide application prospects in biology and the environment. However, the mechanism of 1 O 2 formation, especially the conversion of superoxide radicals (•O 2 − ) to 1 O 2 , has been a great controversy. This process is often disturbed by hydroxyl radicals (•OH). Here, we develop a molybdenum cocatalytic Fenton system, which can realize the transformation from •O 2 − to 1 O 2 on the premise of minimizing • OH. The Mo 0 exposed on the surface of molybdenum powder can significantly improve the Fe 3+ /Fe 2+ cycling efficiency and weaken the production of •OH, leading to the generation of •O 2 − . Meanwhile, the exposed Mo 6+ can realize the transformation ofThe molybdenum cocatalytic effect makes the conventional Fenton reaction have high oxidation activity for the remediation of organic pollutants and prompts the inactivation of Staphylococcus aureus, as well as the adsorption and reduction of heavy metal ions (Cu 2+ , Ni 2+ , and Cr 6+ ). Compared with iron powder, molybdenum powder is more likely to promote the conversion from Fe 3+ to Fe 2+ during the Fenton reaction, resulting in a higher Fe 2+ /Fe 3+ ratio and better activity regarding the remediation of organics. Our findings clarify the transformation mechanism from •O 2 − to 1 O 2 during the Fenton-like reaction and provide a promising REDOX Fenton-like system for water treatment.

Chiral carbonaceous nanotubes (CNT) were successfully used in plasmon-free surface-enhanced Raman scattering (SERS) for the first time. Further modification of TiO2 nanocrystals on the chiral CNTs successfully realized the recycling of SERS substrate as chiral CNT/TiO2 hybrids. The high SERS sensitivity of methylene blue (MB) over the chiral CNT/TiO2 hybrids is ascribed to the laser-driven birefringence induced by the helical structure, which provides much more opportunities for the occurrence of Raman scattering. The TiO2 nanocrystals highly dispersed on the surface and inside the hollow cavity of chiral CNTs can completely degrade the MB under the solar light irradiation, leading to the self-cleaning of SERS substrate. The present research opens a new way for the application of chiral inorganic materials in plasmon-free SERS detection.

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Hollow metal sulfides have been extensively investigated as photocatalysts for hydrogen evolution reaction (HER) due to their enhanced light harvesting ability and sufficient catalytic sites. However, their HER performances are...