Formaldehyde (HCHO) is a toxic by-product widely generated in industrial processes, presenting significant environmental and health risks. Utilizing solar energy to convert HCHO into hydrogen (H₂) and other clean energy provides a sustainable solution for pollution control and energy demands. In this work, a highly active and low-cost CdS/NiO_x photocatalyst was synthesized in situ and applied for the photocatalytic HCHO decomposition. For the first time, simultaneous generation of H₂ and CH₄ was observed during the photocatalytic decomposition of formaldehyde. The optimal H₂ evolution rate can reach up to 13 mmol·g⁻¹·h⁻¹, with a CH₄ production rate of 175 μmol·g⁻¹·h⁻¹ driven by visible light. The close contact between NiO_x and CdS facilitates rapid charge transfer and separation, leading to exceptional photocatalytic performance. Additionally, an apparent quantum yield (AQY) of 2.4% for H₂ production at 420 nm indicates the high solar energy conversion efficiency of the CdS/NiO_x sample. This study presents a promising approach for the sustainable conversion of harmful formaldehyde into valuable energy resources.

The synthesis and potential applications of nanocarbon materials have attracted much attention in recent years. Herein, we report the design and synthesis of a novel all-carbon conjugated polymeric segment of single-walled carbon nanotubes (poly(cyclo-para-phenylene) (PCPP)) and its first application as an anode material for lithium-ion batteries. The as-synthesized PCPP was characterized by Raman spectroscopy, Fourier transform infrared (FTIR), and other spectroscopies. The electrochemical characterization results show the suitability of PCPP as an anode material for lithium-ion batteries. Theoretical calculations indicate the unique structural and physical properties of PCPP. The realization of PCPP expands the scope of bottom-up synthesis of uniform carbon nanotube segments and their potential applications as new materials for lithium-ion batteries.