Biochar is widely used for the adsorptive removal of Cd from water and soil, but the Cd-enriched biochar produced carries a risk of secondary pollution. In this work, biochar derived from rice straw was used to adsorb Cd from plating wastewater. The Cd-enriched biochar showed a saturated adsorption capacity of about 63.5 mg/g and could be recycled and used in a mesoporous carbon-supported CdS (CdS@C) photocatalyst after pyrolysis carbonization and a hydrothermal reaction. The results demonstrated that the as-prepared CdS@C photocatalyst contained mixed cubic and hexagonal CdS phases, with a considerably lower band gap (2.1 eV) than pure CdS (2.6 eV). CdS@C exhibited an enhanced photocatalytic performance for the degradation of organic dyes under visible light irradiation compared with pure CdS due to its excellent light-harvesting capacity and efficient electron-hole separation. Moreover, the continuous formation of active species (h + , q OH, and O 2 q −) was responsible for the photodegradation of organic dyes using CdS@C. This work provides new insights for the safe disposal of Cd-enriched wastewater and for improving the economic viability of Cd-contaminated resources by recovering a value-added photocatalyst.

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This perspective describes the journey of C–S bond constructions starting from transition metal catalysis through oxidant catalysis, photocatalysis and very recently employed electrocatalysis by using various sulfur surrogates.

To evaluate the overall effect of the neck and torso on the head-related transfer function (HRTF), a simplified head-neck-torso (HNT) model, which consists of a spherical head, spherical torso and cylindrical neck, is proposed and the corresponding HRTFs are calculated using the boundary element method (BEM). The results indicate that the HRTF magnitudes for the HNT model are different from those of the existing spherical head-and-torso model (HAT) above 0.5 kHz, especially in the near-field and contralateral region. The discrepancy in the HRTF magnitudes leads to a discrepancy in the interaural level differences (ILDs) for the HNT and HAT models, which reaches a level of ±10 dB at source distance of 0.2 m. As the source distance increases, the discrepancy in the results of the HNT and HAT models reduces. Measurement on practical HNT and HAT models validates the analysis. Therefore, the neck influences near-field HRTFs and should be included in the near-field HRTF calculation.

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