diff --git a/homeassistant/components/tuya/const.py b/homeassistant/components/tuya/const.py
index e38671ae912..5d2070b9015 100644
--- a/homeassistant/components/tuya/const.py
+++ b/homeassistant/components/tuya/const.py
@@ -87,10 +87,12 @@ PLATFORMS = [
 class TuyaDeviceClass(StrEnum):
     """Tuya specific device classes, used for translations."""
 
+    AIR_QUALITY = "tuya__air_quality"
     CURTAIN_MODE = "tuya__curtain_mode"
     CURTAIN_MOTOR_MODE = "tuya__curtain_motor_mode"
     BASIC_ANTI_FLICKR = "tuya__basic_anti_flickr"
     BASIC_NIGHTVISION = "tuya__basic_nightvision"
+    COUNTDOWN = "tuya__countdown"
     DECIBEL_SENSITIVITY = "tuya__decibel_sensitivity"
     FAN_ANGLE = "tuya__fan_angle"
     FINGERBOT_MODE = "tuya__fingerbot_mode"
@@ -132,6 +134,7 @@ class DPCode(StrEnum):
     https://developer.tuya.com/en/docs/iot/standarddescription?id=K9i5ql6waswzq
     """
 
+    AIR_QUALITY = "air_quality"
     ALARM_SWITCH = "alarm_switch"  # Alarm switch
     ALARM_TIME = "alarm_time"  # Alarm time
     ALARM_VOLUME = "alarm_volume"  # Alarm volume
@@ -207,6 +210,7 @@ class DPCode(StrEnum):
     DOORCONTACT_STATE_2 = "doorcontact_state_2"
     DOORCONTACT_STATE_3 = "doorcontact_state_3"
     DUSTER_CLOTH = "duster_cloth"
+    ECO2 = "eco2"
     EDGE_BRUSH = "edge_brush"
     ELECTRICITY_LEFT = "electricity_left"
     FAN_BEEP = "fan_beep"  # Sound
@@ -222,6 +226,7 @@ class DPCode(StrEnum):
     FAULT = "fault"
     FEED_REPORT = "feed_report"
     FEED_STATE = "feed_state"
+    FILTER = "filter"
     FILTER_LIFE = "filter"
     FILTER_RESET = "filter_reset"  # Filter (cartridge) reset
     FLOODLIGHT_LIGHTNESS = "floodlight_lightness"
@@ -231,6 +236,7 @@ class DPCode(StrEnum):
     GAS_SENSOR_STATUS = "gas_sensor_status"
     GAS_SENSOR_VALUE = "gas_sensor_value"
     HUMIDIFIER = "humidifier"  # Humidification
+    HUMIDITY = "humidity"  # Humidity
     HUMIDITY_CURRENT = "humidity_current"  # Current humidity
     HUMIDITY_SET = "humidity_set"  # Humidity setting
     HUMIDITY_VALUE = "humidity_value"  # Humidity
@@ -269,6 +275,7 @@ class DPCode(StrEnum):
     PIR = "pir"  # Motion sensor
     PM1 = "pm1"
     PM10 = "pm10"
+    PM25 = "pm25"
     PM25_STATE = "pm25_state"
     PM25_VALUE = "pm25_value"
     POWDER_SET = "powder_set"  # Powder
@@ -352,6 +359,9 @@ class DPCode(StrEnum):
     TOTAL_CLEAN_COUNT = "total_clean_count"
     TOTAL_CLEAN_TIME = "total_clean_time"
     TOTAL_FORWARD_ENERGY = "total_forward_energy"
+    TOTAL_TIME = "total_time"
+    TOTAL_PM = "total_pm"
+    TVOC = "tvoc"
     UV = "uv"  # UV sterilization
     VA_BATTERY = "va_battery"
     VA_HUMIDITY = "va_humidity"
diff --git a/homeassistant/components/tuya/select.py b/homeassistant/components/tuya/select.py
index 5154afb9ab5..b0b7aeec2be 100644
--- a/homeassistant/components/tuya/select.py
+++ b/homeassistant/components/tuya/select.py
@@ -274,6 +274,24 @@ SELECTS: dict[str, tuple[SelectEntityDescription, ...]] = {
             entity_category=EntityCategory.CONFIG,
         ),
     ),
+    # Air Purifier
+    # https://developer.tuya.com/en/docs/iot/f?id=K9gf46h2s6dzm
+    "kj": (
+        SelectEntityDescription(
+            key=DPCode.COUNTDOWN,
+            name="Countdown",
+            device_class=TuyaDeviceClass.COUNTDOWN,
+            entity_category=EntityCategory.CONFIG,
+            icon="mdi:timer-cog-outline",
+        ),
+        SelectEntityDescription(
+            key=DPCode.COUNTDOWN_SET,
+            name="Countdown",
+            device_class=TuyaDeviceClass.COUNTDOWN,
+            entity_category=EntityCategory.CONFIG,
+            icon="mdi:timer-cog-outline",
+        ),
+    ),
 }
 
 # Socket (duplicate of `kg`)
diff --git a/homeassistant/components/tuya/sensor.py b/homeassistant/components/tuya/sensor.py
index 06c4a783066..e415d26ad4c 100644
--- a/homeassistant/components/tuya/sensor.py
+++ b/homeassistant/components/tuya/sensor.py
@@ -742,6 +742,67 @@ SENSORS: dict[str, tuple[TuyaSensorEntityDescription, ...]] = {
             icon="mdi:progress-clock",
         ),
     ),
+    # Air Purifier
+    # https://developer.tuya.com/en/docs/iot/s?id=K9gf48r41mn81
+    "kj": (
+        TuyaSensorEntityDescription(
+            key=DPCode.FILTER,
+            name="Filter Utilization",
+            entity_category=EntityCategory.DIAGNOSTIC,
+            icon="mdi:ticket-percent-outline",
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.PM25,
+            name="Particulate Matter 2.5 µm",
+            device_class=SensorDeviceClass.PM25,
+            state_class=SensorStateClass.MEASUREMENT,
+            icon="mdi:molecule",
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.TEMP,
+            name="Temperature",
+            device_class=SensorDeviceClass.TEMPERATURE,
+            state_class=SensorStateClass.MEASUREMENT,
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.HUMIDITY,
+            name="Humidity",
+            device_class=SensorDeviceClass.HUMIDITY,
+            state_class=SensorStateClass.MEASUREMENT,
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.TVOC,
+            name="Total Volatile Organic Compound",
+            device_class=SensorDeviceClass.VOLATILE_ORGANIC_COMPOUNDS,
+            state_class=SensorStateClass.MEASUREMENT,
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.ECO2,
+            name="Concentration of Carbon Dioxide",
+            device_class=SensorDeviceClass.CO2,
+            state_class=SensorStateClass.MEASUREMENT,
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.TOTAL_TIME,
+            name="Total Operating Time",
+            icon="mdi:history",
+            state_class=SensorStateClass.TOTAL_INCREASING,
+            entity_category=EntityCategory.DIAGNOSTIC,
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.TOTAL_PM,
+            name="Total Absorption of Particles",
+            icon="mdi:texture-box",
+            state_class=SensorStateClass.TOTAL_INCREASING,
+            entity_category=EntityCategory.DIAGNOSTIC,
+        ),
+        TuyaSensorEntityDescription(
+            key=DPCode.AIR_QUALITY,
+            name="Air quality",
+            icon="mdi:air-filter",
+            device_class=TuyaDeviceClass.AIR_QUALITY,
+        ),
+    ),
 }
 
 # Socket (duplicate of `kg`)
@@ -845,6 +906,10 @@ class TuyaSensorEntity(TuyaEntity, SensorEntity):
                 self._attr_device_class = None
                 return
 
+            # If we still have a device class, we should not use an icon
+            if self.device_class:
+                self._attr_icon = None
+
             # Found unit of measurement, use the standardized Unit
             # Use the target conversion unit (if set)
             self._attr_native_unit_of_measurement = (
diff --git a/homeassistant/components/tuya/strings.select.json b/homeassistant/components/tuya/strings.select.json
index c1171f81fcb..ada9c528ac8 100644
--- a/homeassistant/components/tuya/strings.select.json
+++ b/homeassistant/components/tuya/strings.select.json
@@ -93,6 +93,15 @@
     "tuya__curtain_motor_mode": {
         "forward": "Forward",
         "back": "Back"
+    },
+    "tuya__countdown": {
+        "cancel": "Cancel",
+        "1h": "1 hour",
+        "2h": "2 hours",
+        "3h": "3 hours",
+        "4h": "4 hours",
+        "5h": "5 hours",
+        "6h": "6 hours"
     }
   }
 }
diff --git a/homeassistant/components/tuya/strings.sensor.json b/homeassistant/components/tuya/strings.sensor.json
index ff246817f61..a11aadba321 100644
--- a/homeassistant/components/tuya/strings.sensor.json
+++ b/homeassistant/components/tuya/strings.sensor.json
@@ -10,6 +10,12 @@
       "reserve_3": "Reserve 3",
       "standby": "Standby",
       "warm": "Heat preservation"
+    },
+    "tuya__air_quality": {
+      "great": "Great",
+      "mild": "Mild",
+      "good": "Good",
+      "severe": "Severe"
     }
   }
 }
diff --git a/homeassistant/components/tuya/switch.py b/homeassistant/components/tuya/switch.py
index 4559bdf3364..ae63830bd8d 100644
--- a/homeassistant/components/tuya/switch.py
+++ b/homeassistant/components/tuya/switch.py
@@ -198,6 +198,12 @@ SWITCHES: dict[str, tuple[SwitchEntityDescription, ...]] = {
             icon="mdi:water-percent",
             entity_category=EntityCategory.CONFIG,
         ),
+        SwitchEntityDescription(
+            key=DPCode.UV,
+            name="UV Sterilization",
+            icon="mdi:minus-circle-outline",
+            entity_category=EntityCategory.CONFIG,
+        ),
     ),
     # Air conditioner
     # https://developer.tuya.com/en/docs/iot/categorykt?id=Kaiuz0z71ov2n